When I got on my computer this morning, I noticed that my desktop background was different. When I went on the internet, I noticed my homepage was different. And now that I check other things, I have realized that my computer set itself on default. All the default options are now in play, and all my customizations have been deleted. Certain game files are gone, and whatnot. Can anyone share with me why this happened?

IE resetting is usually down to spyware. But when it happens to other things, you have something more serious. A virus scan is in order I feel, alhough it may just be a registry glitch.