Like the rest, I would recommend that you simply reformat. However, if you choose not to, then boot up in SAFE MODE and remove everything from the device manager. The reboot with only the CPU, motherboard, RAM, and hard drive installed. Then, add your peripherals one at a time, doing a hard reboot between each installation. You'll probably still have lots of little problems, though.
For next time: As a result of having to reformat so many times, I now keep a ~2GB partition for each OS I have installed. I keep all my other files, documents, etc., on a single, large partition. That way, when I have to reinstall the OS, I can save all my stuff. Sure, it's not perfect, but much easier.
-Aaron