Linux OS, with a home modified/upgraded processor with 32 cores and a clock speed of 14.3Ghz.
Good for about 30 seconds before being consumed by fire.
Amusingly, Tim Allen uses Macs - as did his character on the show. And Tim Taylor never managed to blow up his Mac.
http://www.timallen.com/actor/press_archive/
And a Harley V-Twin. I don't know what that would do for a computer, but he'd put it in anyway.
Of course, it would require one hell of a cooling fan, and you wouldn't want to run it with the windows shut and without robust hearing protection.