Can't undo some settings after running the VMWare OS Optimization Tool

[MaxStr]

I need to make one change to a single user's VDI to enable thumbnail image previews in Windows explorer. This was something I had disabled using the OS Optimization Tool, but now I can't figure out how to get this setting reversed. The only "undo" I see is to undo all the settings. I've changed all the settings in the registry and GPO that I could find related to this to no effect. It's even missing the option in explorer. It's supposed to have this menu option:

But the VDI (same image but post-optimization) looks like this:

Any ideas?

[a_p_]

I think the following OSOT optimization needs to be reset to "0"

<step name="Turn off Thumbnail Previews in File Explorer"

      description="Enable this policy, Disable Thumbnail Previews in File Explorer."

      useCaseCatagory="VisualEffect" useCaseLevel="0"

      category="recommended" defaultSelected="true" runOnOs="16">

  <action>

    <type>Registry</type>

    <command>ADD</command>

    <params>

      <keyName>HKLM\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer</keyName>

      <valueName>DisableThumbnails</valueName>

      <type>REG_DWORD</type>

      <data>1</data>

    </params>

  </action>

</step>

André

[MaxStr]

I have, to no avail. I've reverted every local GPO policy I could find, and removed any registry entries. I've gone through the list one by one and reverting anything that remotely looks like it might affect thumbnail icons. I think the Optimization Tool makes some changes that are not documented, because when I do a full "undo" of all changes, it restored the thumbnails. In the end, it was quicker to just issue the user a new VDI.

And to whomever develops the Optimization Tool: Please add the ability to undo individual settings!

[VMwareN0ob]

Does anyone know what it takes to restore the thumbnail view? I set the reg key disablethumbnails to 0 and even deleted but it keeps coming back? I ran the optimization tool and don't have a way to revert the changes it made and can't figure out what settings need changed to allow the thumbnails again.

[BarryUWSEFS]

I ran into this exact issue early last year and figured out the registry setting to re-enable thumbnail view. I am sorry to say I cannot remember exactly what I did but I figured it in OSOT using the "My Templates" tab where is basically shows you exactly what registry changes are made for each setting. I left notes I believe in the OSOT comments section but cannot find them. However maybe this will get you on the right track: https://blogleodegroot.wordpress.com/2020/03/07/explorer-thumbnail-view-disabled-after-running-osot/

[TechMassey]

I can help shed light on this issue and the general workings of the OSOT Fling. The OSOT implements its settings in four specific areas. 

OSOT Target Locations

1. Local Policy
2. HKLM - Reg for Local Machine
3. HKCU - Reg for Current User
4. HKCU (Default User Hive)

First, note number 4. The OSOT does not simply enable local policy or create registry keys. It targets every location relevant to the setting. Add to the fact that changing the group policy setting does not remove the entry in the default user hive and you have a reoccurring issue without obvious solution.

The second and most crucial item is the OSOT never stops at simply targeting the specific policy setting to enable/disable. It targets the feature and any related settings to that feature. If you re-enabled the feature, it will often not be at full functionality. This is a thorough approach but makes reversing challenging. 

In the case of the Thumbnails, enabling or deleting the disable reg key is not enough. Root cause is the Thumbnail feature can't function if it can't cache the created thumbnails to the thumbs.db. See attachment for details and once removed from Default User Reg Hive, it will stop regenerating. 

[TechMassey]

I can help shed light on this issue and the general workings of the OSOT Fling. The OSOT implements its settings in four specific areas. 

OSOT Target Locations

1. Local Policy
2. HKLM - Reg for Local Machine
3. HKCU - Reg for Current User
4. HKCU (Default User Hive)

First, note number 4. The OSOT does not simply enable local policy or create registry keys. It targets every location relevant to the setting. Add to the fact that changing the policy setting does not remove the entry in the default user hive and you have a reoccurring issue without obvious solution.

The second and most crucial item is the OSOT never stops at simply targeting the specific policy setting to enable/disable. It targets the feature and any related settings to that feature. If you re-enabled the feature, it will often not be at full functionality. This is a thorough approach but makes reversing challenging. 

In the case of the Thumbnails, enabling or deleting the disable reg key is not enough. Root cause is the Thumbnail feature can't function if it can't cache the created thumbnails to the thumbs.db. See image and updating the default user registry hive should keep the issue from reoccurring. 

 

[TechMassey]

I can help shed light on this issue and the general workings of the OSOT Fling. The OSOT implements its settings in four specific areas. 

OSOT Target Locations

1. Local Policy
2. HKLM - Reg for Local Machine
3. HKCU - Reg for Current User
4. HKCU (Default User Hive)

First, note number 4. The OSOT does not simply enable local policy or create registry keys. It targets every location relevant to the setting. Add to the fact that changing the policy setting does not remove the entry in the default user hive and you have a reoccurring issue without obvious solution.

The second and most crucial item is the OSOT never stops at simply targeting the specific policy setting to enable/disable. It targets the feature and any related settings to that feature. If you re-enabled the feature, it will often not be at full functionality. This is a thorough approach but makes reversing challenging. 

In the case of the Thumbnails, enabling or deleting the disable reg key is not enough. Root cause is the Thumbnail feature can't function if it can't cache the created thumbnails to the thumbs.db. See image and updating the default user registry hive should keep the issue from reoccurring. 

[BarryUWSEFS]

Yes that looks right. I had figured this out almost a year ago and couldn't remember all the steps. Thanks.

[VMwareN0ob]

Thank you very much for replying to this thread gentleman! Although my issue persists.

TechMassey, I Greatly Appreciate your detailed information, I didn't even think about the default user reg hive coming into play. But can you please expound on this section as I didn't find any group policy or visual effects in this hive as outlined, do you know specific key names by chance? When I loaded the default hive I only found two keys as listed below that had to do with thumbnails, I disabled them to 00000000 but still the issue persists:

[HKey_Users\temp\SoftwareMicrosoft\Windows\CurrentVersion\Policies\Explorer]  "NoThumbnailCache"=dword:00000001

[HKey_Users\temp\Software\Policies\Microsoft\Windows\Explorer]  "DisableThumbsDBOnNetworkFolders"=dword:00000001

The key causing me the grief is the DisableThumbnails found in [HKLM\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer], it keeps getting enabled with new users and this particular key can't be found in the default user hive so I'm missing something. When logged in if I disable this key I'm able to see the 'Always show icons, never thumbnails' option under Windows Explorer Folder Options > View > Files and Folders, when the keys is enabled this option is hidden to the users so they're unable to disable.  

Many thanks in advance!

[TechMassey]

Hey @VMwareN0ob, 

I believe I found the root cause for the misbehaving registry value DisableThumbnails

 [HKLM\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer]

It didn't make any sense, all group policy settings for thumbnails are under the user configuration. However, the only way its regenerating is if its defined in group policy on the machine configuration. Yet, there is no listed policy setting. 

Well, turns out you don't need a definition, the OSOT had updated the local machine policy file, C:\Windows\System32\GroupPolicy\Machine directly and dropped this in there: 

Computer
Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
DisableThumbnails
DWORD:1

This is causing the registry key to continue regenerating. I'm attaching a screenshot, with the specific OSOT setting. You have two options, one is update the OSOT template and set value to 0. Second option is the below blog post, which walks through using lgpo.exe (MS Utility) to update the policy file. 

How to individually modify and deploy local GPO settings (LGPO) - Brooks Peppin's Blog

I did test out lgpo.exe but if you are in the position of just changing the OSOT template. I would go that route for simplicity. 

[VMwareN0ob]

Thank You So Very Much TechMassey!!!

I used the lgpo tool and this work beautifully! I never figured out the OSOT tool and that dang thing has caused me so much grief after using that I won't ever use it again.

I really appreciate your help with this and wish I could buy you a beer or lunch for your awesome effort! So at the very least please accept my virtual high five pat on the back sincere thank you as you saved me brother! I wish for nothing but the best of luck always coming to you for helping others like myself!

Be Well!

[sjesse]

The optimization tool is not an easy button, you should take time to understand what its doing, as it is more efficient then doing all the optimizations your self but using without   forethought can cause problems, I've done that as well. Take snapshots in building your images so you can easily fall back if something doesn't work correctly.

[VMwareN0ob]

Thanks sjesse! You make great points and I appreciate it!

I've learned quite a bit and now know the ramifications of the power of the optimization tool. I now am a snapshot master as I create so many now to test before moving forward. 😁

[Jubish-Jose]

I am seeing a similar issue, but the thumbnails seem to be not showing only for OneDrive folders which are synced. E. g., we have configured to sync Known folders (Desktop, Documents and Pictures) to OneDrive. Any image on these locations doesn't seem to show thumbnails. All other locations work fine.

I saw a few users report this issue as a bug with OneDrive and turning off 'Files on Demand' fixes it, but interestingly for us this issue is seen only on an OSOT optimised image. 

Looking at the latest OSOT tool, I don't see a setting to disable thumbnails, but not sure if its doing it without showing in the OSOT UI.

If anybody has any inputs on how to resolve this, please help.