dimension 8300 hangs at starting windows during reformat

Hi all I ran into a problem that I can't seem to figure out, and any help would be greatly appreciated! I'm running a dell dimension 8300 and I can't reformat cause it hangs at the starting windows before it gets to the screen where you see the partions. I've tried everything from writing zero's to the hard drive, repartioning using "Partion Magic", Formating it on another working pc and installing windows to the hard drive, testing memory, taking out all hardware components not needed, running NTLDR fixer, resetting cmos, nothing I do works I seen a problem like I'm having in another forum and they replaced the motherboard and the problem was gone, but that seems strange to me, cause it wouldn't have anything to do with the motherboard would it? I know there is nothing wrong with the hard drive itself cause I've tested it on another computer.

Thanks for any help