Gav m8..... I had the same problem a while back...did me in for months.
Tryed to Defrag the disc but kept hanging at 65% - this usually is not a good sign and means your drive is probably on it's last legs
I ended up replacing the HD and upgrading my ram - that cured the problem.
It then started to happen again a few months later..... So I ended up ditching my computer and buying a new one. LOL an expensive way of curing the problem but it worked
