Good, glad you got it straightened out.
Sounds like you had some sort of Wareout infection.
I would run that reg file to clear out this entry:
[HKEY_LOCAL_MACHINE\software\microsoft\windows nt\currentversion\winlogon] "System"="kdpua.exe"
The file isn't on your computer and a Google search of it only brings up your post.
It loads everytime you log on.
Good Luck, MrC