I think there is actually something wrong with the machine. Windows 98SE installed, but freezes at startup. If I reset when it freezes, it gives me the normal/safe mode/etc menu the next time, and just choosing normal mode, it boots up fine. O_o The DVD-ROM is brand new. I've run Memtest86 several times; this did reveal that one of the RAM slots was faulty which was preventing the installer from copying files. Once I removed that stick it copied the files just fine and Memtest86 ran for 16 hours without reporting any problems. The power supply seems to be doing fine as reported by both the voltmeters in the BIOS settings menu and a multimeter I attached to the 5V and 12V lines. The hard drive has undergone a write test and several full formats without any errors reported, and neither the Windows installers nor any of the text-mode programs I've been using (e.g. to test the RAM and disks, copy files) have acted abnormally. Copying the XP setup files to the hard disk didn't work. When I run winnt.exe it claims it can't find a big enough (just under 600MB) hard disk, even when the setup itself is on a 10GB FAT32 partition. The only PCI card is a network card. The board has onboard video, sound, and USB. Are there any other tests I should try that might catch some RAM or hard drive errors the others missed? Could the CPU be faulty without everything else going haywire? I can disconnect the USB, but the mouse port is also on that board.