Originally Posted by cavemangrinder
Download and install Ccleaner. Run the cleanup utility as well as the registry cleaner. After that, go to the Startup option and uncheck everything that is not needed, most times the only checked thing would be your antivirus software. Reboot.
This did the trick, thanks!
I guess if it ever slows down so badly again I'll just run the cccleaner and clean it up.