explorer.exe corrupt after virus, no permission to replace

Caught a virus and have been trying to clean it (http://www.bleepingcomputer.com/forums/topic244813.html) but since infection there has been no explorer.exe process on boot-up so I have no desktop icons or taskbar.

Was told to post problem in this forum --

Was instructed to overwrite it in C:\WINDOWS from other locations explorer.exe backed up, but explorer.exe could not be located in C:\WINDOWS\ServicePackFiles\i386\ or
C:\WINDOWS\system32\dllcache\

(the virus deleted it from both locations after the first time I tried to copy it.)

I just tried to copy a clean version of explorer.exe (from a different computer transferred by USB stick) over the corrupted explorer.exe in the C:\WINDOWS folder. However, I could not delete it or copy over it -- I just got a error "Windows cannot access the specified device, path, or file. You may not have the appropriate permissions to access the item."

Can not click on it to start the service (same error).

Any help would be appreciated.

I have been able to access files through the task manager and my computer may still be infected.

Thanks.

Malware and the cleaning process...may result in damaged system files.

I would try a repair install of XP myself...but you could also try running the sfc /scannow command.

How To Use Sfc.exe To Repair System Files - http://www.bleepingcomputer.com/forums/t/43051/how-to-use-sfcexe-to-repair-system-files/

Louis