VMware VCAP7-DTM 2021 Study guide and exam experience…

There’s not much information online to assist if you’re studying the VMware DTM track – last year I wrote a guide for studying VCP-DTM and having recently passed the VCAP-DTM Deploy I am sharing my experience below to help you prepare. You’ve probably already discovered Patrick Messenger’s VCAP-DTM Deploy Study Guide which is full of useful information, read on for my thoughts.

What is the VCAP Deploy exam like vs VCP?

VCAP Deploy is 100% hands on technical lab based exam. Unlike VCP, there are no theory or multiple choice questions. You are presented with a VMware HOL virtual lab which is very, very close reflection of this: HOL-2151-01-DWS – VMware Horizon – Getting Started with App and Desktop Virtualization and contains numerous mis-configurations within the Horizon stack (think connection servers, master images, AD/GPMC, pools, farms etc). You have 205 mins (3:25hr) to answer 28 questions. This may seem like a lot of time, and if you’re at VCAP level you’re probably a proficient engineer who can type fast and work quickly in vSphere but don’t be fooled! I have around 7 years experience with Horizon and ran out of time on the first attempt. The main ‘lag’ is getting used to the lab interface. Each question has a number of advisory comments which tell you what service or appliance you’ll need to log into in order to fix the issue (which I felt was generous!) as well as the required credentials – so in this respect there is some guidance as to where your focus will need to be. In most cases there are a list of requirements (which helps a lot) and limitations around what actions you should or shouldn’t do in order to complete the question – for example ‘Do not enable provisioning’ or ‘Use the default options unless specified’ and this helps provide scope. As you’d expect there’s a handful of easy softball questions ~25% at the beginning and towards the end of the exam, and the remaining ~75% are more involved and will require multiple troubleshooting steps to fix. I would strongly recommend you spend the first 20-30 mins of the exam skipping all the lengthy questions and cover the single-task questions. However, some questions are subjective and will require that you really think about what the ‘best practice’ is e.g. tune an instant clone image for a given use-case.

How to Prepare: My approach…

vMug, HOL, home labs and first attempts…

Unless your employer is covering your exam fees or training ,you’ll be forking out the best part of £400 to sit the exam – the VAT bites at checkout. I suggest buying a vMug advantage membership for $200 (sit on the vMug website for 10 mins and you’ll get a 10% discount popup appearing) – then use the 2x VCAP vouchers @ 20% discount. I think I’ve only ever passed 1 technical exam (no, not ITIL v3 Foundation) on the first take (CCNA Part Deux!) and if you’re half smart ‘you know how much you don’t know…’ or something like that – anyway, with this in mind I sat the VCAP (no revision) to dip my toes and test the water. I spend 8 hours a day doing work in Horizon/ESXi so I felt fairly confident I would achieve an acceptable score for a first try – I failed with a score of 220 – but the experience was hugely valuable and I didn’t really expect to pass first time as I know some of the topics covered features I’ve not touched for a few years (and thus, got rusty with) and in particular vIDM – I’ve never used Workspace ONE.

Prior to the first attempt I had considered forking out £1k on buying server equipment to build a nested home lab environment to study for this – I would recommend doing this if you’ve only got a few years experience with Horizon and perhaps haven’t ever setup an environment from scratch – it’s hugely valuable and will prove useful if you’re working on a VCP (DTM or DVC). However, for VCAP I don’t think this is really necessary – the money is better spent sitting the exam, particularly because the aforementioned HOL provides just about all of the functionality you need to get up to speed on the blueprint. All of the tech tested in the exam is available in the HOL and thankfully you’ll be using all the latest Horizon 8 features in the HOL, but be aware – the exam tests Horizon 7.X so you’re dealing with 7.10-7.13.

Another benefit to forking out for a first attempt is to steer your learning so you understand what depth to study the blueprint at – I tend to over think how much I need to know for technical certifications, and frankly, it can be detrimental to your life energy if you’re wasting time boring yourself digesting KB’s about edge-case configuration problems that appear as frequently as Prince Andrew – it’s highly unlikely these issues (inc Prince Andrew) will be covered on the test. I generally resign myself to the mentality VMware are going to shaft me for exam fee’s but ultimately having the cert will land me good roles as noble and honest recruiters look through the VMware certified professionals on LinkedIn. With this in mind, I started working toward the second and final attempt…

Exam blueprint

The blueprint is nice to look at – why? Because there’s f*** loads of topics that are not included in the Deploy exam 🙂 It is quite encouraging to see (what I consider) a short list of topics to study. I would suggest overlaying each of the bullet points with your real world experience, and then revisit the Horizon 7 documentation – for example: ‘Troubleshooting agent connectivity issues’ – how do you approach fixing a desktop stuck in ‘Customizing’ state, or ‘Agent unavailable’, or ‘Error’ state – checking the network adapter, horizon agent components, post-sync script, hostname issues etc – this is how I might approach the problem, but if I then revisit the VMware KB’s to look at their best practice steps – there’s additional actions you may not consider e.g. using telnet and nslookup to check DNS resolution to the connection servers – approaching revision in this way will be beneficial as it forces you to consider what you already know and build on it by providing more ideas you can apply in real world situations – which is really what an exam should be about (and it’s refreshing to invest time on a cert that isn’t based on multiple choice…).

The exam problems are formulated around the Horizon 7 documentation as a framework, so refresh yourself on the core features available in horizon and how to configure them – I’m mirroring parts of the blueprint below but this is the backbone of what you should know:

  • Kiosks: preparing the connection servers and creating kiosk clients
  • RDS and Instant Clone Pools/Hosts: setting up application pools, entitlement, instant clone, VM-hosted apps – what settings are available when you setup these features, and how would you test they work?
  • Instant clone pools: pool settings, pool operations, enabling 3D features, HTML access, entitlements, master image creation and preparing an image for deployment including optimizing the hardware and software.
  • Connection Server configuration: backups, storage, authentication options, using vdmadmin, services, troubleshooting replication/ADAM issues.
  • Log files: know how to collect log files from horizon client, agent and appliances (VIDM, UAG, Connection server etc) in the horizon stack.
  • Global entitlements: configuring and exporting.
  • Horizon Administrator: understand the admin console and how you can configure global settings.
  • Horizon Helpdesk: what features are available and how do you use them?
  • Troubleshooting issues with instant clones/agent availability: unable to connect to a VM, installing the horizon agent, dealing with VMware Tools issues.
  • Desktop performance: a bit of a subjective topic – but you should be aware of how to assess desktop performance on a windows machine (what native tool are available to do this…p.s. but you probably never EVER use!)
  • Identity Manager / vIDM: enabling SAML and authentication protocols, adding Horizon resources and syncing objects, entitlement of resources to users and groups.
  • AppVolumes: Appstacks and writeable volumes, managing and using these.
  • Group Policy/AD: A few questions require some AD and group policy administration.
  • ESXi – consider best practices for maintaining uptime for a horizon environment – what features might you configure in vSphere to provide some redundancy?

Second (and third) attempt…

I spent a couple of hours each night for a couple of weeks going over the steps above and at my resit, felt confident in what to expect. On the second attempt I invoked-wisdom and took the below approach. This concludes the post and I hope you get some use from this, I highly recommend studying the VCAP as it’s actually like being at work for a few hours and, because it’s hands-on you’re not wasting time learning acronyms and theory that you’ll never use again.

1/ Immediately fire up Chrome and open tabs for all core appliances, setup RDP sessions to connection servers and open GPMC and AD.

2/ Skip through all the troubleshooting/configuration questions and finish the quick (2 requirements or less) questions.

3/Copy/paste all the vdmadmin -help output into a text file and save it on the desktop of connection server – this prepared me for crafting the answers to several questions and have the UNC path to the vdmadmin dir at hand. The keyboards were crap at the testing centre and you can’t use ctrl+c to copy so get in the habit of right click > copy.

4/Look out for gotcha’s or silly requests in the phrasing of test questions – anticipate ‘typical’ mis-configurations in whatever issue you’re looking at.

5/ I flagged a couple of questions with VMware because I felt the wording was very poor/confusing – obviously there is an expectation of competence with a VCAP, but there are also multiple ways to answer a couple of the questions and I feel I fixed a particular group policy issue with a perfectly acceptable solution that I would implement in the real world, but it was not the answer VMware were expecting. My advice here is to try and consider what is the path of least resistance with a given fix i.e. what can you do to minimize the amount of configuration changes whilst still addressing the problem?


I passed on the third attempt with a score of 300/350 – I had hoped to do better but a pass is a pass..! Onto the Design exam and further posts to follow.

Good luck and thanks for reading.



Configuring Windows Defender AV for VDI

Windows Defender AV for non-persistent instant clone desktops is a lightweight and free AV solution for VDI that is growing in popularity as an alternative to typical third party options as people move to O365 and want to align themselves with Microsoft across their software stack.

Below is a quick guide on how to configure Defender for Endpoint (not ATP) which is a free version of Defender included with E3 O365 licensing using.

A file share is used as the source for definition files. I recently had to setup a proof of concept of this for a client who had been using McAfee ENS and we saw a notable improvement in performance and overall desktop experience.

The guide does not cover how to configure VM’s to use MMPC, WSUS , Cloud based definitons or ATP/MAPS.

Environment: VMWare Instant Clones, Win 10 1909.

What you’ll need

  • 1x SMB file and an endpoint for handling the scheduled tasks needed for Defender definition updates
  • 2x scheduled tasks, one to perform the definition download and unpack, and a second to clean-up old definitions. Both scripts provided.
  • VDI specific Defender settings that are configured on local group policy on the master image, and remaining settings configured on domain group policy.

Before getting started..

  • Check you have the latest ADMX templates for your OS.
  • Use a clean build, ideally with an image that has not had any AV agent previously installed.

Step 1: Setup a share and scheduled tasks to download, unpack and clean-up definitions…

Identify a virtual machine/server/desktop or some endpoint that will be responsible for running the scheduled tasks for fetching definitions and storing them in an SMB file share. The endpoint will require internet access and I refer to this machine as the management VM.

Create an SMB file share to store definitions.

Setup a file share that will store the unpacked definitions. The below example resides in C:\wdav-update on the management VM. I recommend using the same folder names as this will tie together with the download script that will be used later on.

Share permission: Authenticated Users: Read

Folder Permission: Authenticated Users: Read/Execute, SYSTEM: Read/Writed

Get-SMBShareAccess -name wdav-update result should mirror the above

*IMPORTANT* if you provide FULL CONTROL to the folder or share, then you may experience the definitions being automatically purged by the child VM’s after they self-update, making the definitions unavailable at next boot . From my limited testing this behaviour appeared to be by design can’t be controlled by any GPO settings, so avoid this by setting the NTFS permissions correctly.

Create scheduled tasks to download definitions

Microsoft provide the following PS script which handles downloading and unpacking of definitions. There is an alternative script available here but I found the below script does the job and is easier to understand. Adjust the value for $vdmpathbase accordingly, but do not change the [0000…] folder naming convention. This is required otherwise the child VM’s will not be able to parse the folders and will fail to self-update.

$vdmpathbase = "$env:systemdrive\wdav-update\{00000000-0000-0000-0000-"
$vdmpathtime = Get-Date -format "yMMddHHmmss"
$vdmpath = $vdmpathbase + $vdmpathtime + '}'
$vdmpackage = $vdmpath + '\mpam-fe.exe'
New-Item -ItemType Directory -Force -Path $vdmpath | Out-Null
Invoke-WebRequest -Uri 'https://go.microsoft.com/fwlink/?LinkID=121721&arch=x64' -OutFile $vdmpackage
cmd /c "cd $vdmpath & c: & mpam-fe.exe /x"

Add a clean-up task…

I configured the below task to clean-up any definition files older than 3 days. Configure this as a scheduled task to run daily.

Get-Childitem "C:\wdav-update" |
 Where {$_.CreationTime -lt (get-date).adddays(-3)} | Remove-Item -recurse -force

Tips for configuring the scheduled tasks:

-Configure definition update to run every 2 or 4 hours , typically MS publish new definitions twice per day, around 8-12 hours between each update.

– If the scheduled tasks are failing, ensure the account used to run the task (local SYSTEM or service account) has internet access – you may need to allow unauthenticated traffic from your management machine if using the SYSTEM account. If you use a zScaler/Proxy device and authenticate clients using a .pac file then you may need to launch IE as the SYSTEM account (on your management VM) and configure the .pac file accordinalty. To do this , download PSExec and run the below command to launch IE in the context of SYSTEM, then configure the .pac file in IE settings.

psexec.exe -i -s "c:\program files\internet explorer\iexplore.exe"

Step 2: Configure Defender local group policy settings on your master image

Defender for non-persistent VDI relies on several local group policy settings being baked into your image to ensure they are available at boot time. Configure the following 5 settings via gpedit.msc on your master image.

Location: Computer Configuration\Administrative Templates\Windows Components\Windows Defender Antivirus\Security Intelligence Updates

IMPORTANT: You must configure Define security intelligence location for VDI clients and Define file shares for downloading security intelligence updates . If you do not configure both, the service will not work.

Values to use:

Define the order of sources for downloading security intelligence: FileShares

Define Security intelligence location for VDI clients: \\yourfileserver\wdav-update

This concludes the minimal settings that are required on the master image.


  • You may want to use LGPO.exe to export a template of the Defender settings for your environment for quick setup in future, or add to an MDT task-sequence for your image builds.
  • If your master image has picked up policies you don’t need or for some reason you’ve had your hand forced to use a crappy image – you can wipe all the local and domain policy by running the below command (elevated). This will wipe all local policy WARNING – do this at your own peril (it will remove OSOT optimizations and all domain+local policy). Remember to re-join to domain and update policy afterwards.
    • RD /S /Q "%WinDir%\System32\GroupPolicyUsers" && RD /S /Q "%WinDir%\System32\GroupPolicy"

Install A BASELINE set of defender av DEFINITIONS

  • If your enterprise has never used Defender before and/or has used a different AV product to date, then it’s highly likely you’ll have domain policy in place to disable Defender and/or your base image will have no pre-existing Defender engine/definitions installed. In this case, you may have to install a baseline definition pack so the Defender engine is activated in the build. This may not apply to all environments but I experienced VM’s failing to update on their first boot because no existing definitions were installed. If this happens, Download the latest definition set from Microsoft and install the mpam-fe.exe file – this will install a definition pack and give you an engine status/last updated point to work from.

Step 3: Configure Defender domain group policy settings…

There’s a plethora of settings for Defender and I won’t cover every setting here. The high level suggestions are covered in the Microsoft blogs – so refer to these, but also be aware that services like MAPS and ATP rely on many of the options available – and we’re not configuring these services in this blog post – only the ‘barebones’ AV product. Some examples of VDI-friendly settings you may want to use are below.

Important: do not configure any of the settings configured in Step 1 on the master using local policy on our domain group policy.

\Windows Defender Antivirus

  • Turn off windows Defender: Disabled
  • Randomize Scheduled tasks times: Enabled


  • Allow users to pause scan: Disabled
  • Check for the latest virus and spyware security intelligence before running a scheduled scan: Enable

\Security Intelligence Updates

  • Specify the interval to check for security intelligence updates: 2 hours

Step 4: Verify that it all works!

So lets recap on what we’ve done;

  • We’ve setup a file share and it’s populating every 2 hours with the latest definition files, unpacked, and ready to be read by our VM’s. We have the necessary NTFS and share permissions in place to make our \wdav-update share accessible from the VM’s and it can be read/written to by the SYSTEM account and/or your service account responsible for running the scheduled tasks.
  • Your master image has the necessary local group policy settings required at boot so the VM’s should be reading from the share and self-updating at every logon, and this should be reflected in the Virus and Threat Protection console in Windows on the VM’s, example below.
  • Your domain group policy settings are configured to manage things like scan times, quarantine behavior, UI and notifications etc and critically you’ve checked the Disable Windows Defender policy is set to disable..!

Spin up your VM’s and check the below log file – search: UpdateEngine – here you can see the subfolders in our definition share being traversed. The log output Skipped verification….Due to PPL is expected and this does not indicate an error. Any errors will be indicated in the entry that begins: UpdateEngine start:


Virus & threat protection settings should show Last Update: today’s date

To Hell and Back with Hybrid AD Join for VDI

*Update 22/01/22 After much effort spent getting this to work at a customer site, it turns out there was never any need to have conditional access enforcing VDI devices to be hybrid-joined. By turning off the conditional access policy that checks the device is Azure-AD joined, there was no longer any issue. Note, if you’re using a zscaler you’ll need to configure source IP anchoring as well.

*Update 31/07/21 After migrating a customer from Appsense to VMware DEM I had to find a new method to perform the hybrid join. The below article now provides two methods for performing the join.

Read this post if you’re having problems performing Hybrid Azure AD join on non-persistent VDI. This post covers the how to configure Hybrid AD join on VDI , how we discovered it was broken and a clean solution to fix it.

The running environment was Windows 10 1909, VMWare Instant Clones on Horizon 7.10, with zScaler proxy (.pac files).

For the solution, click here or scroll to end of article.

How to configure Hybrid AD join and why it might be failing for you…

In our case, hybrid AD join was always broken – we just hadn’t noticed because the device join was successful which is all that is required for O365 services to work (Outlook gets a license – everyone is happy!) but the user PRT token (which I’ll refer to as user-join) was failing – which, if you have InTune in place for MDM policies and all that fancy stuff – you may find these devices are broken when the VDI is in use.

Microsoft offer very little guidance on how to implement Hybrid AD join on VDI but Google yields a lot of negative feedback from folks implementing this for VDI. This VMware thread was helpful in our discovery, and the guidance from Microsoft is helpful, but not as detailed as it should be.

Microsoft’s suggestions are:

Implement dsregcmd /join as part of VM boot sequence.

DO NOT execute dsregcmd /leave as part of VM shutdown/restart process.

  Define and implement process for managing stale devices.

We used a start-up task to perform /join. 

A .bat file or powershell can perform the join as follows, and configure this to run as a start-up task. Note, the task should be ran under the context of the SYSTEM account, and ensure your network is configured to allow this traffic (see zScaler section).

dsregcmd.exe /join

Master Image

You should ensure your master image does not perform an AAD join at all.  You should run the /leave command  as SYSTEM account  prior to sealing your image and taking a snapshot, although we would often forget to do this. Whether this contributed to the issues covered, I’m not sure. Additionally, some threads suggest your master image should not be domain-joined – in our case, the master image IS domain joined, but was NOT AAD joined.

Use PSExec to perform a /Leave command as SYSTEM account:

Psexec -I -s dsregcmd.exe /leave

zScaler .pac on VDI for Hybrid AD Join

If you’re using a zScaler to manage internet traffic you may find that Hybrid AD join fails because the traffic is sent from the VM’s under the context of the SYSTEM account and if no .PAC file is configured against that account, then it will fail (unless you allow unauthenticated traffic on your zscaler devices). If we also throw into the mix that Microsoft recommend you join AAD during device start-up – your user will not have authenticated to zScaler when the /join takes place, so you must configure this.

On your master image, launch Internet Explorer as SYSTEM account, and then manually configure the .PAC file manually. Download PSTools and then run the following command from an elevated cmd prompt:

Psexec -I -s “c:\program files\internet explorer\iexplorer.exe”

The above steps explain how we were configured for Hybrid AD join BEFORE we discovered it was not working. Read on for the discovery, and adjustments we made. Click here for the solution.

How to identify a VM has failed Hybrid AD Join

As a large enterprise with multiple VDI sites managed by different teams, we discovered some sites were performing the /join during the ‘Desktop Created’ stage of the logon process (i.e. once the user is logged In and desktop shell fully loaded) – in these pools we saw the device join was successful,  but user join (PRT token) was unsuccessful – this is because  the user was not logging into an AAD-joined device, so the device was deemed unauthorized to receive a PRT token.

  1. Open cmd prompt and run: dsregcmd /status 
  2. Review the output –note you may also see that the Tenant Name is blank in your output. The device will show as joined, but no PRT/User join had taken place –

Device State shows successful AAD join:

User-join has failed and the AzureADPrt token is not present.

Contrary to MS guidance we experimented with adding a /leave command at logoff – on these pools we saw the object in AAD was updated more accurately in Azure – the ‘Last Activity’ times reflecting the join/leave times of when the desktop sessions were in use.  Howeverthe underlying lesson here is that the device must be joined first then the user is logging into an authorized device and a second /join should take place to fetch the user PRT token.

On the pools configured to use a start-up taskwe found the device join would periodically fail – but this became more frequent as time passed until we had complete failure of all devices in a given pool.

VM template objects flooding Azure AD

We searched AAD to compare on-prem device names to their records in AAD and discovered we had a ton of VM’s joining AAD under the machine name of itXXXX – this is the internal template object which is created by ESXi when a new snapshot is published to a desktop pool. AAD was being flooded with these objects every time we changed the snapshot on a desktop pool.

VM’s were joining AAD successfully (device-join only) but their ID did not match their counter-part object in AAD – instead, it matched the internal VM template.

 At this point we knew that when a new snapshot was published, a new AAD object was being created with the VM’s template account ID. Additionally, it proved the /join was taking place too early in the logon process (at machine start-up) – and instead of joining the hostname of the VM that is provided by QuickPrep (e.g. PROD-VM-1)  the ID of the instant clone template was being used to join the machine to AAD.

To verify this:

  1. Open AAD and search for device name: it

Note, this applies to VMware Instant Clones environments only, Citrix and Hyper-V hypervisors will use a different provisioning process, check your vendor documentation to know what to search for)

Template VM objects in AAD –

Duplicate VM device ID’s

Another symptom of this issue was VM’s would recycle their Device ID – we found the same Device ID (after the device had joined AAD) was in use by other VM’s in the same pool. Presumably this is a hangover from previous symptom.

  1. Take 2 VM’s from the same pool, open CMD prompt and run dsreg
  2. cmd /status, compare the device ID’s on both devices – are they identical?

Verifying AAD Join process

To check if your VM’s are joining AAD with an incorrect computer name:

  1. Check the local VM event log Applications and Services LogMicrosoft/Windows/User Device Registration for event ID 335.
  2. Note, the computer name is itXXXX , user SYSTEM.

Let’s recap what we’ve learned so far:

  • VM’s are joining AAD with the wrong computer name
  • AAD is populated with stale records for our VM’s
  • Our VM’s are recycling device ID’s
  • The User-join (PRT token) is not working

After several hours of toil, testing and swearing, We tried moving the /join to different stages of the logon sequence, but only found Start-up to be ‘successful’ for the device-join. During testing we removed the /join altogether – and low and behold, we discovered the VM’s were still joining AAD – this is because there are 3 scheduled tasks baked into the Windows 10 1909 OS to perform auto-AAD join. 

Microsoft don’t tell you this in their VDI guide because they prefer ‘the Community’ to figure it out…they’re real nice like that.

Configuring Hybrid AD for VDI the right way! #how-to-configure-hybrid-ad-join-for-vdi

Method 1

1/ Perform the /join operation TWICE, once at Start-up, and again before the desktop shell has loaded.This ensures the the Device and the User PRT token are both issued succesfully.

2/ Ensure the dsregcmd.exe /join operation is managed by your profile management tool. Don’t try to mix combinations of scheduled tasks/group policy/profile tool.

3/ Delete the Automatic Device Join scheduled task. This was the root cause of all our pain. The task will perform a join under user context and has 2 triggers – a ‘special event’ and at logon.

4/ Always perform dsregcmd /leave on your master image. Ideally, avoid the master image from joining AAD in the first place.

5/ (Optional) Add a /leave command at logoff of the VM. This is unsupported by Microsoft, the only benefit we found from including this was the ‘Joined’ and ‘Last Activity’ timestamp was kept up to date in Azure AD – but again, not supported.

6/ (Optional) Set the machine GPO ‘Windows Components/Device Registration/Register domain joined computers as devices‘ to disabled. This helps keep things tidy and you can be confident the join is only handled by your profile management tool.

**Alternative Method**

I recently had to decommission Appsense for a customer and move them to VMware DEM. In doing so, the method described above had to be changed. Although DEM can run tasks at Startup of the VM (it hi-jacks the native group policy startup/logoff scripts) which isn’t suitable for performing a /join because the template account for the pool is then joined to Azure AD. Which we don’t want. Thanks to some feedback on the DEM forums, I’ve found the below method works nicely:

1/ Configure a .bat file that has a /leave and /join. You’ll call this as the post-synchronization script when you configure the pool. Example file.

cd c:\windows\system32
dsregcmd.exe /leave
dsregcmd.exe /join

2/ Make the file available on your master image, ideally in the C:\ root somewhere and configure it as the post-synchronization script for the pool.

3/ You should now see the devices populate in AAD when the pool is being composed. When a user logs in , because the VM is now ‘trusted’ the PRT token should be issued. Microsoft does not support the /leave as part of non-persistent devices so I’ve ommitted this. It is possible to add a /leave command (perhaps as a shutdown script), but we’ve discovered no issues with leaving the devices joined in AAD indefinitely.

Master Image configuration

Step 1: Delete the Auto-Join scheduled task in Win 10 1909

  1. On your master image open task scheduler: Microsoft > Windows >Workplace Join
  • Delete the Auto-Join task – this must be deleted and not disabled – because it’s a system task.
  • The remaining 2 tasks should be left in their default state – they should not require any manual intervention. If these tasks are disabled or not present on your image – then check OSOT or group policy if these are being deleted by an upstream policy.

Step 2: Remove your master image from AAD

  1. Launch psexec from an administrative command prompt using: psexec.exe -i -s dsregcmd.exe /leave
  2. You may see the below exit code 0.
  3. Confirm the /leave was successful by checking AAD – you should not see the machine account, and the /status output should be as below.

/status output when device has left

Step 3: Remove existing itXXXX or stale records from Azure AD

  1. Remove any of the stale device records from AAD. This should include the itXXXX devices , and any VM’s in pools your going to test in.

Step 4 (optional): Bake your user profile configuration into the master image

If you’re unlucky enough to use AppSense or a similar tool – you may have to bake your configuration into the master image. Other profile management tools may not require this step.

Profile Management Tool Configuration

Step 4: Configure the dsregcmd /join operations

Start-up task:

  1. Configure the 1st /join operation during Start-up of the machine (or machine boot).

2. Scope this to only apply to machines with your VM naming conventions – this ensure the correct devices join AAD, but also prevent the itXXX devices joining (or your master images).  If you have no profile management tool, then this might work with scheduled tasks or a group policy object, but we did not validate this.

Pre-Desktop task:

  • Perform a 2nd /join operation during the ‘Pre-Desktop’ stage– this is the point at which user authentication has completed, but the desktop is still loading. This should ensure the PRT is issued to the device, and also provides a backup to one of the scheduled tasks (re-sync) which does the same thing.

Has this fixed it for you?

1/ We no longer need to delete ‘stale’ AAD objects – there is only 1 AAD object per VM. Each VM joins to the same AAD object – no duplication, no dodgy device ID.

2/ When a new snapshot is published, we did not see the itXXXX devices appearing in AAD (clean joins!).

2/ User-join was always successful – this is probably because the Auto-Join scheduled task is not interfering with the registration process.

I hope this helps someone, if you find other solutions or suggestions to improve on this find I’d love to know

Everything you need to know about the VCP-DTM 2020 Certification Path

My tips for saving money, what you’re really paying for, study guide and advice for passing the VCP-DTM 2020 qualification!

The following post covers my personal experience in studying for the Official VMware Certified VCP-DTM 2020, achieved June 2020, the following steps are covered:

Step 1:Consider a vMug Membership

Step 2: Studying for Foundations 6.7 exam

Step 3: VMware Instructor led training [on demand]

Step 4: Preparing and Passing the VCP-DTM 2020 Exam

Step 1. Consider buying a vMug Membership…

vMug membership will provide around £650 of overall savings for the DTM certification track and provide resources for a home lab and is a great insurance to have if you fear failing the exam (like I do)…

  • vMug costs around $200, but do a quick Google for vMug discount codes prior to signing up to save a further 10% on the signup fee.
  • You save around £550~ on the official VMware instructor-led training [on demand] or In-Class routes.
  • You get a total of 4x 20% exam discount vouchers – 2x for Foundations 6.7 and 2x for any VCP exam – saving you around £30 per re-sit, if needed. You also receive discounts for VCAP if you’re on that path.
  •  You get evaluation licenses for a broad range of vProducts – including vCenter, Horizon Standard, View Composer and Identity Manager – which covers most of what you’ll need for the DTM route.

Sound great! But what’s the catch?

  • Bad News: vMug Evaluation licenses DO NOT cover the VCP-DTM 2020 blueprint technologies! Considering VMWare want people to have hands on experience with their products, but won’t let you spin up a lab environment at home to use their latest innovations, I found it pretty disheartening to realise I’d spent $200 but wouldn’t be able to setup a home lab for JMP components:

Is there any good news?

  • Sort of. You do get evaluation licenses for ESXi, View Connection Server, Identity Manager, View Composer and vCenter Server which will let you build a linked-clone lab environment and this will definitely help you . More on this further down.
  • Below pictures of what the software catalogue looks for vMug Advantage members:

Step 2. Pass the vSphere Foundations Exam

The foundations exam is a prerequisite for the VCP certification and is a an open-book exam (not invigilated)  exam blueprint for vSphere Foundations 6.7 can be found here.

It’s worth noting that, you’re experience may be with Horizon, or vROPS, or some other suite of products – but the focus of the Foundations exam is aligned with the VCP-DCV certification path– there are barely any questions on DTM related content. This threw me off (I failed it twice) – so be aware that you basically become ‘primed’ to study for the DCV path by virtue of undertaking the Foundations course.

Naively I had expected the Official Course Guide to provide a decent level of detail for what is covered in the Foundations exam but the book does not cut the mustard.  I ended up relying on the below resources far more than the OCG, so below are my recommended study materials in order of preference. Good luck!

Study Materials for vSphere Foundations 6.7 2019


Undoubtedly the best resource you can use if the VMware Knowledge Base ; remember to filter each article by the release version you need. Exam questions are formulated from KB articles, so I recommend prioritising these as your primary material before referencing any related books, websites, third party study guides.


VMware Technical and Whitepapers cover Best Practice, Details Design Documents (DDD’s), Overviews and Explanations of all things VMware. I’d covering each exam topic but equally, taking notes from each paper for real-world application. Ask yourself which vSphere features your current client or workplace utilises and consider the ‘why’ behind each design decision. This’ll make your study a lot more relevant.


VMware Technology Network is a useful forum area moderating by VMware staff and there’s plenty of real world Q&A to reference.


Recommended Study Books

Mastering VMware vSphere 6.7 – Nick Marshall

Useful for: a great deep-dive reference into each feature in vSphere 6.7. Contains implementation steps, explanations and recommended practice for every feature covered in the Foundations exam blueprint.




vSphere 6 Foundations Exam Official Cert Guide – VMware Press

Good for: Giving a primitive understanding of each technology area. However, this book is littered with mistakes – from grammar to incorrect question answers and dodgy screenshots from legacy versions of the web client. It’s written in a conversational tone which is great, but massively let down by its brevity and lazy proofing. I suggest you don’t rely solely on this book (as I did…).



Building A vSphere Home Lab On Your laptop!

This guide to creating a complete VMWare home lab on your laptop is truly excellent. You build an 2-node vSphere home lab and can run it entirely embedded environment on your home laptop. You may need to buy some more RAM to accommodate it , but it’s money well spent and you can utilize your vMug evaluation licenses to run the latest vSphere components at home! In relation to the exam, it is well worth going through the motions installing and setting up the ‘core’ vSphere and Horizon components – this aids massively for both exams – believe it or not, there’s plenty of exam questions (in Foundations and VCP) focused around what happens during installing or what options/steps are built into the install process.

As a guide, I have a Dell XPS 15 i7, 32gb RAM, 500gb SSD (free space) and was able to run 2xESXi node w/ Composer and Connection server.

Step 3: What is the VMware Horizon 7: Install, Configure, Manage [V7.7] – On Demand training ?

Bearing in mind my experience will give a slight bias to this information – I have around 6 years experience with Linked clones, AppVols, and 1yr with Instant Clones and UEM  in large enterprise environments. I personally found the training to be a bit below par considering the cost and I had higher hopes considering this is meant to be the ‘Real McCoy’ training bundle.

I paid £3000~ for the On Demand training, and yes that price included the vMug discount – and yes, I did feel like an absolute vMug for paying that. However, given my employers have paid me good contracting rates for several years, it was a small investment in the grand scheme of things, and I wanted to compare how they perform as a training provider and gauge how much new knowledge would be imparted to me for paying that kind of premium.

Course Delivery

The training modules are hosted on the VMware Learning Zone portal, and broken down into 10-15 min videos with Linus Bourque taking you through (nearly) all components of Horizon, but not all DTM exam topics are covered in the Horizon 7.7 On Demand course. The below screenshot is an example of what to expect.


The delivery is sometimes a bit predictable – the instructor generally parrots what is written down on the slide adding some colour occasionally, however, the slides do cover about 70% of the course in high level, but I’ll reiterate vROPS and Identity Managerare not covered in the training or labs. It took me around 16 hours to complete the entire On Demand course.


Each module has a few multiple choice questions which do not count towards your qualification. There is a Final Assessment after you complete all the labs and training videos which is covered further down this page.

My opinion?

For the more experienced Horizon admin 5+ years, I think you could skip this and save yourself the expense – but if you’re keen to have the VMware stamp of approval and be ‘fully’ certified, then you’ll have to pay for it. The training does hit the mark for someone with 6 months -1 year hands on experience of Horizon, which is what it’s geared for – you’ll get a good overview of the features of Horizon, what it can do, how it operates and you can walk away with that ‘how can I apply this at work?’ feeling.

For the more experienced administrator, I would avoid paying for it at it’s current price . Particularly if you can combine a home lab setup (for View Composer, Linked Clones) with real world experience in an enterprise. Personally, I will be avoiding paying for anymore VMware training for future VCP certifications. I preach as short sermon on my opinion of vendor training in general at the bottom of the article.


What are the On Demand lab exercises like?

When you give away £3k you half expect to be granted some decent learning experiences in return , after all, the fee is equivalent to 1 term at university – so what do you get?


A vSphere environment with RDSH hosts, AppVolumes Manager, UEM and Win10/Win7 VM’s for creating Linked and Instant Clone pools.

This covers around 70% of what you need to study for the certification, but it doesn’t have any infrastructure for Identity Manager and vRealize Operations Manager – more on this later.

The tasks set during the labs are basic and anyone with 1-2 years experience will have already performed 99% of what is asked of you. Some example tasks include – installing the Horizon Agent into a master image, running OSOT to optimize the OS, create an AppStack and assign it, create an Instant Clone and Linked Clone pool, install UEM (now DEM) and test it – in short, much of the bread and butter tasks to stand up a Horizon environment.

Room for improvement?

Yes. If you want to give customers value for money, I would expect more real-world tasks to be included in the training (isn’t that the idea?).  It’s also disappointing that vROPS and vIDM isn’t covered at all in the training or the labs – but accounts for about 30% of the exam? In general, the labs cover installing the components but not ‘from scratch’ as its target audience may have expected. Typically the server or manager element for a service is already setup, and you’re tasked with installing and configuring the agent component into a desktop.  If VMware took the time to add a few extra steps to their existing walk through’s it would build a richer learning experience, and I think they fall short on this.

Suggestions for improving the labs

-Install and configure View Composer – create a DB and ODBC, install Composer, point it to the DB, link it to vCenter. This would help prime te understanding of the high level steps needed to configure other Horizon component likeAppVols, vCenter, View Connection Server.

-vROPS and Identity Manager are completely ignored. There is zero information in both the training and labs that covers Identity Manager or vRealize Operations Manager. The exam blueprint includes these topics but you are you’ll have to use the free VMware Hands On Labs (HOL) to familiarise yourself with these technologies and read the KB articles around installation and configuration.

-The DEM (UEM) labs should include how to create predefined settings, writing application templates, how to use the application profile tool and configuring Horizon Smart Policies, to name a few.

-How to update an AppStack and edit it’s properties to mount on different OS’s – valuable for techies involved in OS migration projects!

-How to create an instant clone RDSH farm and app delivery mechanism.

What is the VMware Horizon 7: Install, Configure, Manage [V7.7] – On Demand Assessment?

At the end of the On Demand training course there is a ‘Final’ assessment – don’t be worried by the ‘finality’ of it – it’s a 95 question assessment which repeats all of the questions from the earlier end of module tests – so you’re answering questions you’ve already experienced! Bonus: for each question you have the opportunity to correct your answer twice, so there’s a pretty low chance of failing this, but if you passed each end of module assessment without trouble, you will be fine. As far as I am aware, it can count towards being VMware Certified.

Step 4. Prepare and Pass the VMware Professional Horizon 7.7 Exam to achieve VCP-DTM 2020 Certified Status

If you’ve paid for the On Demand training course, you will receive a free attempt to sit the exam. If you choose not to undertake the training then you’ll need to schedule the exam through Pearson Vue and pay $250 per take. If you fail, you have to wait 7 days before your next resit.

Is the On Demand training enough to sit the exam immediately after completing it?

No it’s not, before you start revising for VCP-DTM 2020, watch the video series: Horizon 7.7 Professional Exam Prep in the VMWare Learning Zone. The video cites numerous VMware papers to reference for revision and as a silver lining, the presenter makes several exam question slips along the way .

My usual tact is to read the ‘Install/Configure/Overview-flavour’ KB articles of the given topic and make notes from these and then refer to books and third party study guides to reinforce your notes. Also, try to image the type of exam question that could be formulated from the KB article you’re reading.Equally, VMware can’t test people deeply on technologies that aren’t easily accessible through vMug or an evaluation license – in our case Instant Clones, AppVolumes, UEM and RDSH – so work within these limitations by not pouring hours into the edge-case issues or configurations – because it’s likely it won’t get covered. Remember it’s a Professional level cert, not Expert/Architect/Specialist.

I would personally recommend trying to answer the following questions for each technology area in the blueprint, and also refer to the ‘By the end of the training candidates should be able to‘ list which is available alongside the blueprints for the training courses (not the exam blueprint). This list is included in my study notes (highlighted yellow bullets) available below.

For example, for AppVolumes:

  • What are the OS and database minimum requirements for install and/or any pre-requisites?
  • How do you install the manager/agent and what does a typical/custom/complete installation include?
  • How do you perform routine operations (e.g. creating, updating, deleting an appstack).
  • What are a few typical troubleshooting issues you might come across with this technology whilst installing/configuring it OR whilst deploying/using it? e.g. Appstack not mounting, what happens when a user vs computer assignment conflicts, writable volumes not attaching and so fourth, what causes the agent component to fail connecting to manager/server, and so forth.

I hope you’ve found this article useful in deciding whether to study the VCP DTM 2020. This concludes the article, but below are my thoughts on vendor training and how it could be improved. If you have an opinion on that, I would be keen to hear it


Final Thoughts on IT training…

The following is not targeted at VMware , but IT vendors in general and their training methods. Most enterprise IT vendors have a team of staff with 100’s of years of combined experience between them; so why do the customers and learners continue to be subject to unimaginative examination and training experiences? Can you remember an Associate, Professional or Administrator level certification that gave you raw, technical skills that you were able to apply at work? I can’t. It’s pretty unimaginative and lazy in 2020 to be expecting people to memorise minimum requirements or what steps are correct to perform action X? – It risks the brand reputation and risks losing your target audience’s interest in the vendor/technology/IT, so why do vendors continue to fall into this trap? What purpose does memorising a bunch of settings serve that is not replaced by Google?

A thought; we live in the attention economy, so getting 100% of someones attention to read your course guides, study your products and write about it online (the irony is not lost on me) is massively valuable – look at the click bait industry! IT vendors have willing participants who will voluntarily pay to indulge in their product developments, buy their books and pour hours of energy into the hope it will give them cutting edge skills – so why do vendors not capitalise on this? Training presents an opportunity to convert a learner/customer into an ambassador/salesman/woman but only if the recipient receives what they are looking for or what they have paid for – real world, bill-paying skills. If vendors took time to tap into their in-house support functions and correlate what common problems they see with their products, understand what real world customers are doing with their tech and how it addresses business needs, then ask themselves, how can we incorporate this into our training ? that would be a good start.

I feel there is a gaping void in the lower-tier certs to address this and I’m yet to study a cert from any vendor that has broken this mould. I can’t speak for VCAP, CCNP, MCSE, CCEE level certs as I haven’t worked on these yet (and my expectations are already marred – see the problem?). The age of the Pavlovian memory games must end!

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Welcome to Desktop Surgery – The End User Computing Blog For Aspiring Techies

This blog is largely a dumping ground where I can validate the hours spent pouring over IT virtualization and EUC challenges, hopefully saving you time and effort whilst learning some new tricks.

It will also contain anything else that’s useful for EUC and desktop support technicians.