When my IE version was IE10 my Avast Free version was 2014.9.0.2007 I had a problem with my Avast Online Security causing slow loading of homepage google. I then reported this issue to Avast Support and submitted a ticket and I submitted some log files via Avast GUI. When Avast made an update to 2014.9.0.2008 and I still had IE10 all of the issues were gone. When Microsoft released IE11, Avast Online Security and IE11 works fine.

I did a complete and clean reinstall of Avast 2014 Free Edition.