In the last few weeks, my Windows 7pro desktop has been getting the dreaded BSOD on a pretty regular basis. Eventually the whole shebang shat itself, could not even get the damn thing to boot up. Anyway a computer tech mate of mine managed to get it up and running, he had to do a complete re install of the OS, which I thought might have been the case. He tested it, in all conceivable ways, ran the memtest for 7 iterations, and that confirmed it was not RAM. I got it back last Monday and ran like a top for 4 days, and you guessed it, BSOD again. I have nothing attached to the computer, it is basically a virgin! Only running Office, and my ESET internet security.
So I rang him and he was dumbfounded, looking like it might be the Motherboard which is around 5 yrs old, so no way is there any replacements available. So any of you gurus out there have any ideas on this one.

Obviously any help much appreciated.