Unable to Start WSUSservice using Local System Account

I was using WSUS on Windows 2000 Server until now without any issue but today Ive found that WSUSservice is not running using Local System account. It simply gets hanged and timeout, i have checked out log and description of the error says following:

The Update Services service failed to start due to the following error:The service did not respond to the start or control request in a timely fashion.

I have tried running service as administrator and WSUS service gets synchronize with upper stream servers and download patches as well but i want to get it running using Local System account as well.

Any help???

I have faced same issue previously and have found the cause of the issue as well, in start i was able to get WSUSservice running using Administrator account and restarting WSUSservice using Local System Account but after a restart same issue was reappearing. Later i used Filemon which a software from sysinternals for tracking files that get accessed by WSUSservice . Using this software i found that when i was starting WSUSservice using Local System Account then wsusservice.exe was trying to access C:\Documents and Settings\Default User\Application Data\Microsoft\CLR Security Config\v1.1.4322\security.config and C:\Documents and Settings\Default User\Application Data\Microsoft\CLR Security Config\v1.1.4322\security.config.cch but they were no existing. Where as when i was starting WSUSservice using Administrator account wsusservice.exe was trying to access C:\Documents and Settings\Administrator\Application Data\Microsoft\CLR Security Config\v1.1.4322\security.config and C:\Documents and Settings\Administrator\Application Data\Microsoft\CLR Security Config\v1.1.4322\security.config.cch and installation was successful.

So in short logging with different users was changing environmental variable %APPDATA%,in order to fix the issue you can check out for "CLR Security Config" folder and copy it in to Default User's Profile. Once you do that you should not get any error in running updates using Local System account.

Thanks a lot! Your solution helped me narrow down a problem that I had in one of our application's service.