When I install XP, it reboots about a minute after entering the CD key, and goes back to an earlier stage of the install.
If I try Vista, I get stopcode 5C HAL INITIALIZATION FAILED.
So this might suggest a hardware malfunction. But I could install Win 2000 on it without drama. Although not so useful:
only 16-colour display, and SATA DVD no workee.
Also a live Linux CD goes without problems. Was able to run various benchmarks (CPU, memory, disk).