Did you try restoring your CMOS settings to "default". If so, try making your IDE-0 drive the first boot option. I think the problem is more related towards software, so don't worry too much about the hardware. I am sure that everything inside of the PC (hardware settings) stayed the same whenever the computer was working fine so there was no need to really change anything inside of the PC, just look. Your MBR could also be damaged/corrupt. There is a method of restoring it that i forgot. Maybe someone else can offer some advice on restoring you MBR.