Internet Explorer is the only software I have that does this.
I noticed after thinking about recent installations, it happened after I installed "My Ad Blocker" and I uninstalled it, and it nwo happens much less frequent. I think maybe parts of it are left, even after I manually took outta registry.
I always use SpyBot and Ad-Aware, all updated, on a weekly basis. I run Norton Corportae 8.0, always updated, on a monthly basis. My PopUpCop gets everyhting that tries to get through and rreduces load of these things by 90% I would say. I use System Mechanic to clean registry just as well. Tried to reinstall IE, and system checks, and defrag.
It still happens every so often but less than before ever since the ad blocking software.
I'm very annoyed, will soon throw things at the PC.