Check the memory. This will make a floppy boot so you can run it in Dos http://www.memtest86.com/
If that checks out OK, go here http://h10025.www1.hp.com/ewfrf/wc/softwareList?product=385178&cc=us&lc=en&dlc=en&os=228 and make sure your drivers are up to date...particularly the bios.
