Please post back a screenshot of your maximized Disk Mgmt Drive map and listings, using the Snipping TOol in Start Menu. We can see if its configured correctly from that.
Then start working through these Troubleshooting Steps for Windows 7.
If you withheld installing all Windows Updates after a reinstall then you are not running Windows 7. YOu should install all Updates and run with Updates set to Automatic. The possibility of Updates messing up your PC is less than one in a million so there is something else wrong most likely.
I would look over these steps which spell out how to get a perfect Clean Reinstall - Factory OEM Windows 7
as if you stick closely to them and use only the tools and methods within then you will be assured of having a perfect install. You can then backup a System image in case it becomes irreparable, used to reimage the HD or its replacement in 20 minutes.
Installs should also always be done with only the target HD plugged in, to avoid interference from other HD's. This alone could be a problem which we should be able to see from the screenshot.