I recently installed new motherboard XFX P4XE-MVB along with Celeron 2.0 and 512 DDR PC-2100.
I finally got it running for a couple of days after installing new hard drive but now I am having problems.
The computer starts rebooting itself while running programs. I was running TmpGen encoding an .avi file when this happens. Also, when I am running Sonic MyDVD!
I'ld suggest getting a new case with powersupply, at least 300W, generic should be fine, you should be able to pick on up for about 40$ canadian, or probably 30$ US.