Ok..new PC is up and running, though with an old PentiumD 3.6 in place of my lovely Quadcore Q6600...I will try the Q6600 again tomorrow just to be sure it is indeed faulty. So far apart from a few bios setup errors the PentiumD powered version has run stable and true all day, and I've been installing things into it (man that takes ages)
I thought for a while I was going to have to buy a new video card as the overclocked 7800GTX game card I installed refused to go to my preferred 25600x1600 res, but then I remembered it had two outputs and I switched the monitor feed to the other one and voila, 2560x1600 in full glory.
I still have a lot of setting up to do then see what I can salavage from my backup drive..but at least I have a PC again...if the quad is indeed dead/dying I'll buy another, since iX chips came out the quads are not so expensive now so I can give this beast a bit of a boost before I need to upgrade it to the christmas I7 monster I have planned.
1st things 1st though, I need to try to get hold of all my utilites and tools that were lost and not backed up (you can't backup installed software)...so that's going to be a few days worth of work.
sigh....this is why I HATE upgrading PC's