You end the conversation with:
You guessed it.......
deltree c:\windows
That would not work for two reasons:
non-DOS derived windows versions do not have deltree command, del has finally got /s (delete subdirectories) flag that obsolotes it.
Even if it would exist, that wouldn't do anything, because there is no c:\windows folder, 2k and xp are installed in c:\winnt.
Just so you know how to remove next infestation!
