I Had the following hardware setup:

• Phenom II X4 945
• Asus M4A97
• 4GB DDR2 OCZ
• Radeon HD5850
• OCZ Agility 2 120 GB
• Windows 7 x64 Pro Fully updated (latest drivers and windows update patches)

Then I bought an used Phenom II X6 1090T and installed it without formatting. Since that my computer started BSODing almost every time I'm playing any game and with different error messages, like:

• page fault in non-paged area
• bad pool header
• the video memory manager found a problem
• error in dxgmm1.sys(or something like that)

And when it doesn't BSOD the game simply crashes.

I have tried:

• Updating BIOS
• Reseting BIOS to defaults
• Reinstalling Video Drivers
• Installing the latest DirectX

All that's left is to do a full format and I don't want to do that since it's going to be a lot of work to fine tune windows to my preferences again. So is my "new" processor defective or do I really need to format the computer?

Update: I use a (properly installed) custom cooler from Coolermaster and both the BIOS and the Open Hardware Monitor(Application) attest the CPU is not overheating, so I guess the CPU its defective and since I bought it from a guy over the Internet I'm probably screwed