i also have an idea..
if ur deleting files from say... Windows\System\*.dll or some other system files...
windows has a hidden directory call dll_cache (or something like that)
when u delete a System file, say... openGL.dll
it'll be gone, but when u refresh it, it's back cuz windows restores it from the hidden directory. Either overwrite it in the hidden directory, or delet it from there.
Another thing is... this directory REMAINS hidden even if u have 'show hidden directory'
the reason for this is because it holds the stability of the NT system because it doesn't allow other programs/users to overwrite the NT dll file.
Hope this helps..
Kiz