Although it could have other causes, this is one of the symptoms of
infection by the Swen virus, which has been extremely active lately.
See your antivirus vendor's web site for information and a removal tool
(or instructions); or just go here:
By the way, this is the wrong newsgroup for such questions, being
devoted to discussion of Microsoft Access, the database program.
Normally you'd post such a question to one of the groups devoted to your
operating system.
