Ok i defo. think that its a hardware problem.
and im thinking its my CPU

I got rid of the raid setup and just tried installing on just 1 HDD plugged in. And just flicking through the install menus took an age and each one loaded up slowly!! I mean real slooowww.
Pretty goddamn pissed off at the mo.
I found thant the north / southbridge cooler wasn't on properly or the TIM has deteriated

So Im gonna leave it for the weekend!! im off up north for Sat and Sun. and my bank holiday is goning to be made up of me taking my PC to PCses (lol) and set it all up on a table outside the case and re-tim all the components and start from scratch