Windows 7

I just saw this Gary as I have been busy today with fixing someones oc

but I see you hav e been helped. All I would have done is not to insert the product key on first asked, but later on , but it still worked fine for you so that is ok

as for the rfactor, clean install is better (except the username folder that is , same with other sims...backup the username folders (and other folders that might be important )

welcome to windows 7

^^ O/Clocking you say???
Have had my I5 750 at 4.2Ghz stable as can be for well over a couple of weeks now, it has soaked up everything I have thrown at it and laughed it off in fine style with not one blue screen :O
... the Corsair H50 watercooler is keeping the CPU cool as the stock cooler was at stock speeds (ie. 2.6Ghz) - over 60% overclock, you gotta loooove it!!

I know this will be my future cooler too. Until now I still run my Q6600 at 3.8 or 4.0 Ghz so for gaming it is enough. Maybe next year I will do an upgrade and I am sure to buy that cooler also.

I am REALLY happy with the H50 cooler and for now can only highly recommend it ... in fact I am really happy with my new rig, full stop ... the sum of its parts is far greater than the individual components may otherwise suggest. (specs are listed under another thread here somewhere).
There is still another few hundred mhz to be had out of this i5 CPU without stressing it too much, but I think for now this meagre 4.2Ghz will do me fine ;-))

EDIT: The H50 is dead simple to install too, and as its a factory sealed unit, I will not be having to worry about topping reservoirs up or springing leaks etc.