windows start menu, search functionality is stopped working and showing blank after install OS patch KB5066835.

Hi Mohan,

Thank you for the confirmation. I sincerely apologize that the registry solution did not work.

From your feedback and that of other users (Simon and Anthony), it is now clear that this is a critical bug within the KB5066835 update itself.

My registry solution (DisableSearchBoxSuggestions) was an incorrect guess; the problem is the update itself.

The Definitive Solution (for your 300 servers)

Currently, the only confirmed solution (which you already discovered) is to uninstall the update.

For a related issue on Server 2025, the official guidance from Microsoft is also to uninstall the update as a temporary workaround.

Uninstall the patch: Use the command wusa /uninstall /kb:5066835 on the affected servers.

Block Reinstallation (Most Important):

Go to your Windows Server Update Services (WSUS) (or equivalent patch management tool like SCCM/MECM).

Find the update KB5066835.

Right-click and select "Decline".

This action will prevent this faulty patch from automatically reinstalling on all 300 of your servers. You will need to keep this patch in a "Declined" state until Microsoft releases next month's Cumulative Update to replace and fix this bug.

If this answer helps clarify the issue, please click "Accept Answer" to let others know that the registry solution is incorrect and that uninstalling is the only way to resolve it.

Same issue. Rolling back update does fix the issue so definitely related to the KB5066835. I see all these other people having issues with the updates, but haven't seen an answer from Microsoft. This post is the only one I have found with this particular issue.

Experienced this issue recently on my work machine, IT had to uninstall KB5066835 via recovery tool. Uninstalling via Windows update didn't work. Uninstalling via recovery tool fixed the issue.

Dear Mohan,

This is a known issue that some users have experienced, where the update conflicts with existing search indexing configurations.

You can follow the steps below carefully on one of the affected servers to test the solution.

Workaround: Modify Registry to Mitigate Search Issue

This procedure involves adding a registry key to revert a change introduced in the update that is causing the conflict.

1. Open Registry Editor: Press Win + R, type regedit, and press Enter. Make sure to run it as an administrator.
2. Navigate to the Correct Path: In the Registry Editor, copy and paste the following path into the address bar and press Enter: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Search
3. Create a New DWORD Value:
   • Right-click on an empty space in the right-hand pane.
   • Select New > DWORD (32-bit) Value.
   • Name the new value exactly: DisableSearchBoxSuggestions
4. Modify the New Value:
   • Double-click on the DisableSearchBoxSuggestions value you just created.
   • Set the Value data to 1.
   • Click OK.
5. Restart the Server: For the changes to take full effect, please restart the server. After restarting, the search functionality should be restored.

I recommend deploying this change via Group Policy (GPO) for easier management across all your servers. If you find this answer helpful, please don't hesitate to hit "accept answer" 😉.