But my first guess, would be spyware. It's an ever increasing problem, and all you're seeing now is amature hour. It's going to get a LOT worse in times to come.
Pick your favorite search engine and start reading up on links that crop up for "spyware removal". And be sure to stop using IE, and make Mozilla Firefox or Opera your new browser of choice.
Can someone tell me why a program stops responding, it seems lately it is happening all the time. Is there anything I can do to stop this happening?