When it comes to computer problems, and you're not a moron (which it sounds like you're not), the nuclear option is usually the best way to fix something. Back up your stuff, and reinstall your operating system. With Windows in particular that's something you should do from time to time anyway. It's guaranteed to fix any software-related issue, and the time it takes to do (1-2 hours) is generally less than you'd spend googling the problem, trying bad fixes, waiting for strangers to respond on message boards with more bad fixes, etc.

Not trying to criticize you for trying to fix it, just saying that I've troubleshot a LOT of computers, and in my experience it's not worth it. Computers are just too complicated. Even when you "fix" it, half the time you've just masked the symptom for a while anyway.

So. Take two hours to put your stuff on an external drive, and reinstall your OS. If you still have the problem, it's a hardware issue, at which point you can swap components till failure, and buy a new "x". Or take it to a shop and sign over your first born.

*shrugs* Good luck.