I found some discussions about it and it all revolved about 'customized logon screens'.
Have you ?
In closing, tell what antivirus and anti-spyware tools you have used since this happened.
Bob
Out of the blue yesterday, I was all of a sudden unable to connect to the internet and the message:
"Not enough quota available to process this command"
was displayed.
This message appears after the computer has been sitting idle for a while. When this happens the computer also gives me other problems
1. My Start Menu > Programs display is empty
2. Unable to launch IE
3. Unable to shut the computer down. In fact, the option to shut down the computer or restart is not even available. The only available options are to log off and to log on as a different user.
4. I can open "My Computer", but not access any of the files.
The computer does not lock up meaning the mouse and
keyboard still work. The computer is up to date with all Windows Critical updates installed. I have Updated Mcaffee Virus software and lots of anti-adware programs, but nothing seems to help.
If I turn off the computer or log out then back on, everything works perfectly for awhile (~45 minutes) before starting again.
ANy thoughts? Thanks.

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic