How do I re-enable my USB Bus?

I have done some silly things in my time, but this one is vying for first place. The short story is in an attempt to trobleshoot a USB problem, I went into Device Manager (running XP) and disabled the entire USB bus. The problem is that my mouse and keyboard are USB, and I am totally dead in the water. On the Dell 9100, there are no PS2 connectors for the tried and true PS2 keyboards and mouse. I have tried power cycling (many times), going to BIOS and looking for anything to do with the USB (other than diagnostics), even pulling the battery in a hope to remove any configurations. If it isn't obvious, I can't get back to Device Manager to enable the USB bus. Setup offer me no assistance either. I don't care about destroying data, I have backups.

So the question is posed, how can I re-enable the USB bus from BIOS, or anywhere else for that matter?

Oh, one more tasty tidbit; this is just the first of several issues I buried myself into. The BIOS was corrupted from a nasty virus, and the hard drive is not being reconized. What this means is that if I try to reload XP, I get to the point where it is going to start loading onto the disk, and stops. Diagnostics says the hard drive is OK. At least if I can get the USB bus enabled, I can re-download BIOS, and hope that gets me past the latter hurdle.

Appreciate your time, and worldly knowledge

Brian