Hi
I also believe its Spyware of somekind.
Usually IE should give you some kind of message about whats trying to access the net.
I would download , CWShredder and Hijackthis
http://www.intermute.com/spysubtract..._download.html
http://www.spywareinfo.com/~merijn/downloads.html
Run both of these and Adware
Also - Get Spybot
http://www.safer-networking.org/en/index.html
this stops programs writing to your registry and thus overwriting defaults on your machine.
f4fan