This is a lot like saying that a body part of yours hurts, but not saying how bad the pain is, where it is, how long it's been bothering you oh and by the way, you forgot to mention that you were hit by a bus yesterday. Plus you're not telling us your gender or age or whether that mysterious body part has ever hurt you before.
Yeah, this question is that vague.
Standard response - check your computer for spyware, run a virus scan, and go to an earlier restore point. Anything more specific than that, you'll have to give us more specificity, too.