I agree, you have got a virus that has hijacked your browser. You should first use AVG, avast, kaspersky online anti-virus to remove all viruses on your pc, then try to get 'Spybot - search and destroy' to remove the remaining trace of the viruses, your system should then be fixed. I would suggest you not to use anything like Norton because they remove important system files when infected.... try to heal the files first before removing any files.
