You may have "SPYWARE" on your system. Go to this site and download "Spybot". It should find the problem, then go back to "Internet options" and change the home page to "USE BLANK" or a safe site such as "GOOGLE".
http://www.kujoe.com/blog/freeware/2005-06-01,3,spybot-search-and-destroy-14.php
NetFXcomputing.com
December 2005