Also when you have completed the reinstall make sure you find your chip set drivers for your motherboard, you can normally find them on the manufactures website and also find your comps graphics driver, those are the 2 that i also find even if it is already installed, I never trust graphics drivers that i pull off of microsoft update, i have had to many funky screens after a restart when i download and install one on accident
other then that Windows 7 is AMAZING!!! I have it on both my laptop and Desktop, both running it flawlessly and both craving more from Microsoft lol
Hope you enjoy Windows 7