I had a 486/450 that started locking up, the only solution that worked was to shut the machine down. I tried looking for software that might be causing it to crash. Nothing seemed to help. Since then, I replaced the case with a ATX, with 350 watts. Upgraded motherboard to elite group k7s5a, amd +1800,repartioned hard drive with fdisk, reformatted, re-installed windows 98SE, full version, installed the windows ME upgrade. Recently while still experiencing the lock ups, I bought and installedNorton System Works 2002. When I ran the fix program it found 82 errors that it said could cause the problems I’ve been getting, I told it to fix them. which it did. But I still get the lock ups. It seems to be program oriented. I never know when it will happen. Right now I running off my old hard drive. Which is a Seagate 10 gig. I also have a Western Digital 20 gig. Both hard drive have the same problem. When I try to resolve the problem, I shut down and switch the IDE cable and power. On the 20 gig I have not done the upgrade to windows ME. The only hardware that is original is a soundblaster PCI 128, plextor cd-rw, and floppy drive. I don’t know what else to try. I have 256 megs of sd-ram. Any help would be greatly appreciated.