Need serious help with SIS 648/ATI problem

Friend of mine received his preassembled custom computer.

Here are the specs...

http://www.powertrippin.com/files/finalbox.JPG

Anyways, I was helping him get the latest drivers on and the very last thing we did was enable the large system cache.

He rebooted and his whole file system was corrupted.

So I said, oh **** oh well we'll just reinstall. Booted from winxp CD, at the user agreement where you hit f8 it does nothing, f8 to agee that is.

So we made boot floppies, did the same thing.

We low leveled the hard drive, same thing.

So, the system worked fine when we got it and was stable, but I can't get the system past this windows setup user agreement thing for the life of me.

Any Ideas?!?!?!