Computer blue screens after installing new AMD Phenom II 945

I have just installed a new processor which is a AMD Phenom II 945 to replace my old AMD Athlon 6000+. I have checked and it is compatible with my Motherboard. The last two BSODs error codes are C05 and the other I can't remember! I'm guessing it is my PSU because it is a crap Corsair CX750M. Unfortunately, money is tight so I can't buy a new PSU!

Mobo: GA M52L-S3P
Old processor: AMD Athlon 6000+
New processor: AMD Phenom II X4 945
RAM: 8GB DDR2-PC6400
PSU: Corsair CX750M
OS: Windows 7 Professional
BIOS Revision: F5

Under idle it is 30C. In gaming, it goes up to 50C.