Event ID 1081 Userenv

I am getting the below error at any 2 hours gap time:

Windows cannot impersonate the user. (The handle is invalid. ). Group Policy processing aborted.
User: NT AUTHORITY\SYSTEM
Source: Uerenv

The fast user switching is turned on, and if I log out or lock the computer with WIndows+L then I AM not able to log into any account anymore, the only way I CAN get back in is to restart the pc. The first Userenv error (Event ID 1517) started as a warning, then the error (Event ID 1081) began after some months. ANY IDeas? Thanks.

Since you have a lot of Userenv errors in the Event VIewer, then you can download and install the User Profile Hive Cleanup Service. When you experience slow logoff, you are having profile unload issues. That actually decreased my shutdown time a bunch. And it usually takes anywhere from 10 to 20 seconds to shutdown.

C:\Program Files\UPHClean\uphclean.exe is added.

Usually, the User Profile Hive Cleanup service gets added to Services and uphclean.exe will run all the time. I am one that doesn't like to have any extra services running, but I am sold on UPHClean.

Download details: User Profile Hive Cleanup Service
http://www.microsoft.com/en-us/downl...s.aspx?id=6676

UPHClean v1.6d readme.txt
http://download.microsoft.com/downlo...5ac/readme.txt

Even I am getting used to the Userenv 1517 after every shutdown. But like you, i dont like to have any additional services running. I can imagine that the issue is with my Antivirus program but it would be nice to know what is causing this event errors. Also leaving the events my shutdown time is still very fast.

Try to follow the below links for some solutions:

Troubleshooting profile unload issues
http://support.microsoft.com/kb/837115

How to enable user environment debug logging in retail builds of Windows
http://support.microsoft.com/kb/221833

EVEN I am getting this error message as well. It looks to happen only when i am at the welcome screen and logged in. MOST of the times windows locks me out by refusing my password and the only remedy is to restart. CAn anyone tell me a fix for this error? Thanks

TO solve this issue all you need to do is remove Service Pack KB923191.