Hi I am having the same problem. Computer starts then shuts down. Get the codes 8.b., 9.C.,9.d.,9.E.,9.F. Was using a Hercules 400 watt power supply when the problem developed.Changed to a new Chiefmax 650 watt power supply. Had the same problem when I first built the system but I was using a 300 watt power supply. Went to the 400 watt worked for while now no joy with either 400 or 600 watt. Am running windows XP pro,have an AMD 3000+ socket754 processor,ATI radeon X1300 pro sapphire graphics card, OEM cd-rom,Sony 8x/4x/32x cd-burner, western digital 40g hard drive. Can any one help with this problem? thanks