Windows 11 Start menu/Taskbar hanging

[reformatt]

Couple of Windows 11 machines have come in this week with the same issue. After you login, the taskbar will not appear (or just be a black bar). No access to Start Menu. Task Manager (use CTL+SHIFT+ESC) works, however the Performance stats seem stuck with CPU on 100% for Task Manager itself. Trying to exit Task Manager result in it hanging as well. No issue if you boot into Safe Mode.

First machine, tried many things to no avail (System Restore from last Windows update, rebooting in Diag mode, trying to reinstall Windows Apps via Powershell). In the end, I did an in-place upgrade with a 23H2 installer on USB which solved it but I found Task Manager still hung on exiting. Clean install wasn't an option on this machine.

2nd machine same issue. This time tried to uninstall the last Windows update (which was KB5036620). I wasn't able to do this in normal mode as it just kept hanging via Control Panel. Had to do from Safe mode, Control Panel, Programs and Features, View Installed Updates. Removing KB5036620 and rebooting restored the Taskbar and Start Menu. This isn't a complete solution, as Task Manager does not show any updates in Performance and still hangs on closing it, and Windows Update does not work at all (checks for updates forever).

So not sure if it is this latest KB update, but something definitely borked from MS recently for Windows 11.

Nothing at all I've seen so far from MS about it either.

[mcplslg123]

Not faced yet,so honestly speaking no idea. Any update on manufacturer's website?

[reformatt]

First one was a HP, other was Dell. Only thing in common is Windows 11 23H2 and the last bunch of Windows updates.

[reformatt]

Ok tackled this again this morning. I investigated the Task Manager not updating first. This was resolved by some info on this page:

https://learn.microsoft.com/en-us/an...ng-waitchain-d

After removing all the DAFUPnPProvider#uuid entries in the HKLM\SYSTEM\ControlSet001\Services\DeviceAssociationService\State\Store registry key, Task Manager now updates correctly and exits cleanly when closed. There were many entries on this system, so it took a lot of DEL and ENTERS to get rid of them all. I had to disable the Device Assocation Service and reboot though as I could not kill this process.

Windows Update also now working again as well. I let in reinstall KB5036620 and rebooted to see if this was an issue with this update. Well Windows rebooted fine? So I have NFI.

To summarise:

1. Booted to Safe Mode, uninstalled KB5036620 update via Control Panel/Programs and Features/View Installed Updates
2. Boot normally, remove those entries for Device Association Service.
3. Allow Windows Update to reinstall it.

[reformatt]

Another machine in today (this time Surface Laptop 4) with same problem. As this is a MS lappie, it has Bitlocker defaulted on. So an addendum to this thread is that you have to dump the Bitlocker recovery key, as you can't get into Safe Mode without it.

Easiest way is to use Task Manager (CTL+SHIFT+ESC), Run New Task, CMD (with Admin privileges) and run

manage-bde -protectors C: -get

I redirect it to a txt file on a USB stick so I can pull it up on another machine.

manage-bde -protectors C: -get > D:\BLkey.txt

I also found that you have to fix the Task Manager deadlock issue (i.e. where it's not updating) otherwise reinstallation of this update will cause the same problem again. The first machine I did came back, as I hadn't worked out that part of it at that point (and the customer was sweating me to get the laptop back).