Hi PiotrW,
Disable system protection and then Run a System File Checker (sfc.exe), this will scan all protected Windows files to verify their versions have not been overwritten or damaged, and if so will replace the compromised version with a fresh copy. To run it, click Start/Run and type ‘sfc.exe /scannow’ (without the quotes but with the space between the ‘e’ and the ‘/’). Alternatively, you can click start/Run and type in CMD and click O.K., when the black window opens type in “sfc /scannow”. You will need to insert your Windows CD into the drive to enable sfc to effect the repair. Sfc.exe will just stop without any other sign than the statusbar is gone! And remember, never ever delete svchost.exe again, do not even think about it. Repairing it, well try this:
Verify Windows Update Service Settings
* Click on Start, Run and type the following command in the open box and click OK
services.msc
* Find the Automatic Updates service and double-click on it.
* Click on the Log On Tab and make sure the "Local System Account" is selected as the logon account and the box for "allow service to interact with desktop" is UNCHECKED.
* Under the Hardware Profile section in the Log On Tab, make sure the service is enabled.
* On the General Tab, the Startup Type should be Automatic, if not, drop the box down and select Automatic.
* Under "Service Status" on the General tab, the service should be Started, click the Start button enable it.
* Repeat the steps above for the service "Background Intelligent Transfer Service (BITS)"
Re-Register Windows Update DLLs
* Click on Start, Run, and type CMD and click ok
* In the black command window type the following command and press Enter
REGSVR32 WUAPI.DLL
* Wait until you receive the "DllRegisterServer in WUAPI.DLL succeeded" message and click OK
* Repeat the last two steps above for each of the following commands:
REGSVR32 WUAUENG.DLL
REGSVR32 WUAUENG1.DLL
REGSVR32 ATL.DLL
REGSVR32 WUCLTUI.DLL
REGSVR32 WUPS.DLL
REGSVR32 WUPS2.DLL
REGSVR32 WUWEB.DLL
Remove Corrupted Windows Update Files
* At the command prompt, type the following command and press Enter
net stop WuAuServ
* Still at the command prompt,
type cd %windir% and press Enter
* In the opened folder, type the following command and press Enter to rename the SoftwareDistribution Folder
ren SoftwareDistribution SD_OLD
* Restart the Windows Update Service by typing the following at the command prompt
net start WuAuServ
* type Exit and Press Enter to close the command prompt
Reboot Windows
* click on Start, Shut Down, and Restart to reboot Windows XP
Damian