Did you run Adaware 6 on the system before the probelm started, if yes than do this:

At the Recovery Console command prompt, type the following lines, pressing ENTER after you type each line:
cd system32

copy userinit.exe wsaupdater.exe

exit


How to install and use the Recovery Console in Windows XP
http://support.microsoft.com/default...b;en-us;307654

There's another method to try and fix this if you were running adaware.