I've read about those drivers in other forums, and some (sorry, no links) were able to get into Safe Mode and some were able to do the F8/boot to the last known configuration. The thing to do is get rid of those drivers, run checkdisk and then install the Hyperion drivers. Upgrades, according to VIA, to the Bus Master IDE are supposed to be included with the Windows XP service packs. You may indeed end up having to reformat or at least do a repair install.