Unpredictable and constant freezes

This regards a Compaq Presario 5001cl desktop with a 650 Duron Processor and 128 meg of ram running Windows ME. This machine is freezing everywhere, even while trying to start from a boot disk. (This really freaks me out) I’ve run scandisk and repaired an error #2001 Fat binaries do not match message. Have been able to do a selective start-up routine and had the machine up for about 2 hours yesterday until it crashed again. Switched power supplies and the video card from an identical working unit to no avail. This thing crashes more than Evil Kneivel. At this point I’m about to trash it. Does anyone have any suggestions?