Originally posted by: Vortex22
Was the memtest one of the ones you boot from a floppy with and run without starting up windows? If so, and it locked up during the test, I would vote for 1- Bad motherboard, or 2- Bad RAM.
Originally posted by: iwearnosox
The easiest way to do this is through process of elimination. Remove all hardware that's not required, then begin to replace each component with a different one until it gets stable. I'm sure you don't have all these things laying around, but if you could borrow them or buy and return them at a store.