My computer seems to reboot all on its own without no warning of a problem. I've replaced processer, memory, harddrives, video card, cpu fans, etc........ I can't figure it out..... System specs Amd 2600 ( 2 ) Maxtor 40 gig harddrives MSI 9250 video card 1 gig of ram MB KT4AV Windows XP Pro Service pack 2 all latest drivers and updates
try downloading and running memtest 86 and running it for about an hour, see if you get any errors in your RAM http://www.memtest86.com/
I don't know the voltage options for that motherboard off-hand, but you might try looking under something like "Frequency and Voltage Settings" and see if you have an option relating to VDIMM or DRAM voltage. DDR runs 2.5-2.6V by the JEDEC standard (an electronics standards group), but you might find that bumping it up to 2.7-2.8 may get rid of the errors. That's a safe voltage level, so don't worry about frying the RAM, just don't go any higher if you happen to have it (and I don't think you would on that board---if any voltage options).
Ok... tried the new voltage settings and it would not work...... seemed like the computer ran slower. So I reset them back to auto....... tried both 2.7, and 2.8
Someone on another site had a very similiar problem and, after trying everything as you have, this eventually was the fix...his computer would randomly shut down without warning as well...
also try to set your CPU FSB to 166, your RAM speed to 166, or 333. have it set to a certain value, not auto.
for some reason I can't get the FSB for the CPU up to 166........ The processor is brand new as well as the MB....... With the latest Bios update for it........ I've even gone as far as changeing out CPU fans with several different types that say will work with this CPU and are recommended for it.