My compaq presario uses a standard micro-atx board. List your system model number and maybe I can match up a board to your case. You may have to format and reinstall windows with a non hp board. My hp windows was proprietary to the motherboard bios. You may need to purchase a standard windows recovery cd or dvd. Some places sell dell oem xp and vista dvd's which work on non dell boards for $20 or less shipped. Then after loading the software, you can reactivate windows using your old coa sticker number. You may also want to try a different power supply first.