Probably caused by Malware or a search re-direct Rootkit. Install, update, and run these programs in this order. They are all free for personal use, but some have limited functionality in the "free mode" - but those are features you really don't need to find and remove the problem that you have. <br />'''''(Not all programs detect the same Malware.)''''' Malwarebytes' Anti-Malware - [http://www.malwarebytes.org/mbam.php] <br /> SuperAntispyware - [http://www.superantispyware.com/] <br /> AdAware - [http://www.lavasoftusa.com/software/adaware/] <br /> Spybot Search & Destroy - [http://www.safer-networking.org/en/index.html] <br /> If these don't find it or can't clear it, post in one of these forums for specialized Malware or Rootkit removal help: <br /> [http://www.spywarewarrior.com/index.php] <br /> [http://forum.aumha.org/] <br /> [http://www.spywareinfoforum.com/] <br /> [http://bleepingcomputer.com]