Well, I did exactly that. The result was one XP that won't work. AT ALL. Not even in Safe Mode.

then i say you sorry again, but i personally already HAVE deleted dx files from the list and pc worked for me

Sorry I didn't see this topic before. For the case it happens again:

Upgrading directx is no problem, but downgrading doesn't work. As I had to do this, I found a freeware tool called dxbuster. It removed directx completly and after reboot I could install an older directx version, reboot once more and everything was fine.

Oh, I'm talking about Virus98 SE, don't know it will work on XP also ...