[Animal]

Since your boot loader still assumed there was an old copy of Windows installed there was probably old drivers somewhere as well. Mix old drivers with new drivers and you get problems.

Win 98 and Win xp use a completely different OS Kernel, thus the need for seperate drivers yet the drivers are usually have the same filenames whether for a 9x system or an NT system.

If XP is attempting to load a driver based upon the 98 drivers, you'll have problems, most noticeably with your chipset drivers for the motherboard.

Although XP is a great OS, Microsofts best to date, it is a resource hog so you need to be running hardware that can handle it. Assuming that, it's a software problem.

Honestly, I'd look at a complete and clean re install including a repartition of the HD.