It took me a week to fix this because I kept finding the trojan/spyware but than I'd reboot the computer and it would be back. So what I had to do is unhook my router from my modem and run it ('it' being the router) directly to the computer. I then did a "hard boot" of the modem (holding in the 'reset' button on the back of the router for about a minute with a paper clip) and after I logged into it I changed my username and password to something much stronger than "password". I ran my anti-spyware software, deleted the trojan/virus, rebooted the computer, hooked up my router and modem again and viola!! No more problem.
Hope this helps
This should work, but go to the Malware Forum to make sure that you come out 100% clean. This suggestion also points out that malware is causing this issue.