Hello, I'm buying a new motherboard and cpu soon and I know I will not be able to connect my HDD with windows installed and be able to run it fine. I'm upgrading my OEM HP computer. I'm replacing the motherboard and cpu it came with. My question is, if I format the HDD that it came with, will it uninstall the OEM version of windows 7 so I can do a clean install with my new windows 7 CD im buying? Or will the OEM version of windows still linger on the HDD? I wan't to use the same HDD it came with because it's actually very good and would save me money so I don't have to buy anew HDD.