I have a severe problem with this one machine. I reinstalled the operating system on the HD and it worked perfectly fine over another machine. Yet on the one where it had failed it comes up with "Operating system not found." I was guessing it is the motherboard. I fiddled with the RAM as well, to see if a faulty one might be doing it. However, I only did so with the three original sticks that were already in there so they might all be faulty. Would it be good to assume that the motherboard is faulty?
If it was a problem with the mainboard or RAM, I would think that your HD wouldn't come up at all. Sounds like there may be a problem with you BIOS settings.
I would check the BIOS and see if it is recognizing your drive. If not, I'd check the jumper settings on the drive. Is the hard drive on the same IDE cable as another device like the cdrom or another hard drive? Also the IDE cable that connects the drive to the motherboard could be bad. You say the drive works fine on another machine right?
Check your computer in this order 1) BIOS setting 2) IDE cable 3) IDE connector 4) Harddisk Drive Jumper setting, make sure there is no conflicts 5) Motherboard
This is exactly what I would do... If the BIOS doesnt recognize it Unplug and reseat the IDE cables (at the hardrive and motherboard) and check your Jumper settings
