Download and install a spybot sweeper. From the sound of things you have one of the many potential adware programs installed with some form of agent running in the background. Find the agent and kill it.
Also, don't use IE. IE is the worst browser you can use right now. There are tons of security problems and lack of features that are almost a requirement nowdays (popup blockers). Don't bother with 3rd party blockers, use a program that has the blocking installed with it (Opera, Fire#?, Mozilla, whatever).
Anyway, bed time.
:pint: