Sounds like hardware issues, you will need to physically take out the hardware(e.g. sound cards, tv tuner, etc.) just start system with only the bare motherboard, video, ram and hard drive.
Make sure you have the latest drivers, but not beta drivers.
Also spyware maybe?
You can place spybot and free AVG on a USB drive, additionally, you can run a complete scan with NAV (Norton Anti-Virus) Boot Disk: This will check everything BEFORE booting to windows.
You will need a reliable source computer to work from since your main computer seems to be comprimised.
Article forAVG and instructions found here:http://www.computing.net/answers/security/avg-antivirus/17758.html
Microsoft does have an official Windows 7 Support Forum located here http://tinyurl.com/9fhdl5
. It is supported by product specialists as well as engineers and support teams. You may want to check the threads available there for additional assitance and support.
Microsoft Windows Client Team