Free stuff will come more and more with junk installed in the program. The more you install these types of programs the worse it will get.
The old phrase "There is nothing free on the internet" is becoming more true every day.
Some toolbar leftover or piece of software associated with weather bug is what is screwing up IE so go to,
Internet Options in the control panel
Advanced tab at the top
Reset Internet Explorer back to default
See if that helps
Oh and by the way I have used Combofix many many times without disabling the AV successfully.