[John Rogers]

I doubt that the jumpers were changed, also. I am betting it is a virus that has deleted a bunch of driver files such as those ending with a .dll file extension, probably in the Windows or Win98 \System or \System32 sub directories. If you can not see the hardware as noted above then check the batt as it could be failing or have failed. A quick check is to look at the computer's time setting and if it is still current than the batt should be okay and since you said the machine boots up the BIOS is still seeing the hard drive(s). Good luck