I've tried the following: Renamed SoftwareDistribution to SoftwareDistrbutionOld Then installed SP1windows6.1-KB976932-X86.exe from :My link None of these suggested remedies have helped Before that I've run System File Checker, result: Windows Resource Protection did not find any integrity violationts newest log files:My link After tried the following: 1.Stopped wuauserv and crypto services, deleted the “%windir%\softwaredistribution” directory and restarted the services 2.Deleted complitly Norton antivirus then again installed SP1 Any suggestions on how I can find the cause of this?