Run in safe mode...
Then do a scan
and remove all the viruses O:
Other thing that can relate to freezing and BSOD:
-Your not cleaning out your PC from dust. You have to regulary ( 6 months ) to prevent your computer to overheat if its very fast overheated. Blowers are recommended ( Cold air ) but you can also use vacuum cleaner but you have to set it on low else you have a chance you sucks up your video card. Oops

Just joking but seriously dont