Windows 7 Freezing

So I built a pc for christmas, did my research and hoped for the best.
So at first my BIOS would freeze, like it wouldn't restart or anything, just become non-responsive, then i installed 4 120mm extra fans on the side panel to help and it would freeze again on installing windows 7. So finally I tried opening all my windows and blew a big fan in the side and it let me install windows but it still freezes on me like 2 or 3 minutes after I get on. I tried switching HDDs, same thing. I tried switching GPUs, same thing. I switched my power cables from my PSU, same thing. Then I tried to install drivers to see if that's my prob and it freezes DURING install.

anyone please help!!

Computer specs:
Asus P5N-D Motherboard
Corsair XM2 4GB (2x2GB) RAM
EVGA GTS 250 1GB GPU
Western Digital Caviar Black 500GB HDD
Samsung ODD DVD burner ODD
Antec 750w True Blue PSU
Coolermaster Stacker 830 Chassis

Have a look and make sure you plugged the CPU fan power connector into the motherboard it's any easy thing to forget to do

also i would reset the bios to factory defaults and go over all the settings set SATA controller to IDE mode as AHCI seems to be broken

Sounds to me as if someone forgot to use TIM when they installed the CPU heatsink.

It's also easy to not get those little pins into the holes correctly which means the heatsink isn't making proper contact with the CPU. In any event you should pull the heatsink off and make sure everything is right.

Either that or the CPU heatsink fan just isn't plugged in.

Hey thanks for responding everyone! I appreciate it. So to clear it up my CPU was at 46C and my Mobo was at 26/27C
I applied Arctic Silver 5 to it so it does have TIM and my stock CPU fan is plugged in and spinnin'

UPDATE: Happy new year guys!
So I pulled out my heatsink to see what's going on and my brother pulled out his old Core 2 duo 2.66 Ghz cpu and heatsink and we put it on and no freezing!! so then we figured it must be my new heatsink. so we tried my cpu with his older cooler and it still froze. So it looks like my CPU is defective or something. the defective cpu was running at like 46C, this duo is doing 27C hahah
Thanks for your help guys! Time to do my first RMA