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>>;Thanks. I tried an Ubuntu Linux LiveCD and it froze just the same. All the fans appear to be working fine but I will look at replacing them or adding others.>;>
This test has effectively eliminated the primary disk and the OS as potential culprits, suggesting possible thermal failure (though a contemporary BIOS would shout about that usually).
Generally, this is bad news for you. Now it's time to replace the other bits one at a time until you find the real culprit. It could be a memory issue, which would be great from a cost perspective, but more than likely you'll end up replacing the motherboard. I would try RAM first, then video card. If you have any other PCI cards that you can go without, try pulling them first (and leaving them out) to see if it will still freeze up in their absence.
If physical inspection shows spinning fans, then it's probably not the fans, though it could be the sensor on the motherboard probing whether or not the fan is present and operating normally.
Again, bummer, but I bet you'll end up with a new motherboard before you get this one solved. Gateway should be able to provide a factory reconditioned mb for cheap.
Good luck,
--joshua.
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