Blue screens after Win 7 install? Q6600

Hi, I've been running a Q6600@3.0ghz for two years now with no programs..aside from a PS failure. Recently I installed Windows 7 Pro 64 bit. Since then occasionally when I turn the computer on for the first time of the day sometimes it will boot into windows and crash after a few minutes via blue screen of death. Other times it will not boot into windows at all.

Sometimes I have to reseat the RAM modules to get the monitor out of standby on power on. The funny thing is once it's up and running everything seems to be fine.

Originally I thought maybe the overclock or the ram was no longer stable..or one of the RAM modules went bad? I ran Prime 95 blend test with no errors and the max temps on the core was 60C. Is Prime 95 blend test good enough to test the RAM sticks? (I don't have any blank cds right now for Memtest)

I'm thinking maybe there is still bugs in Windows 7 or could my overclock possibly not be stable anymore after 2 years?

Any ideas??