I have an Intel D865PERL Mobo with 3GHz processor (pentium 4) and 2Gb of RAM running on windows xp. the computer ran fine for the better part of a year and a half and then started to randomly shut down (every few weeks it might). the problem got worse to the point where certain programs (Itunes) would almost crash it automatically. I formatted the computer and reinstalled Windows XP. it worked for a while and then started to just randomly shut down again. I didnt touch it for about two months. Recently, i have removed and unhooked every additional piece of hardware besides a video card, dvd drive and hard drive. i have even tried a different video card, different dvd drive and i still have the same issue. I then tried a brand new hard drive but XP would not install properly (either blue screen or could never copy the correct files for installation) I ran a MEMTEST which would crash consistently and so i had RMA replacement of the memory. At this point i was at least able to install XP on the new hard drive. The final step I have taken is a brand new power supply and the computer still has the same issue. It generally will boot into XP but then shut down within a minute or two of operation. I have checked the temperature in the BIOS and the processor is running at about 149 F. I can stay in the BIOS for what seems to be an indefinite amount of time without it shutting down. I figure it is either the processor or the Mobo, but how do i determine that at this stage?