If the BIOS cannot see the HDD, it will not be able to boot from it. Unfortunately, if the BIOS does not see the drive, there is no diagnostic tool that I know of that can detect or repair and...

Just to be sure, do you have anything that can test to see if the battery is good? I've bought brand new dead batteries from Radio Shack before, so it's either more common that you would think or I...

Assuming that the new power supply and motherboard are both working, try to remove all peripheral devices and see if the machine powers on.

All devices being floppy, CDROM, HDD, any USB devices,...

Does the fan come on or just the light?

It sounds like a bad motherboard. Check to see if you have any broken or leaking capacitors. If you aren't familiar with what they look like, they are...

I have found that in most cases, it is better to use manufacturer drivers than use the windows update drivers provided by Microsoft.

Your problem also sounded like one I had on a PC with a...