I read on Avast's website that their Internet Security 2014 was win 8.1 compatible so I upgraded to WIN 8.1. What a mistake.
At first the install was successful but Windows immediately told me that Avast was not compatible with this version of Windows.
I played around for a bit and set up my picture password and then rebooted my PC. At this point, my keyboard (wireless USB, wired USB, and PS2) would not work in win 8.1. My picture password wouldn't work in most cases. Fortunately after 20 tries the picture password worked. Even trying to use the typed password was impossible as the on-screen keyboard would not come up.
Not knowing that the keyboard issue was related to Avast, I spend hours trying to figure it out and actually gave up and decided to work on the Avast issue Windows warned me about. To my surprise when I uninstalled Avast and rebooted my computer worked perfectly.
I am a long time user and proponent of Avast (with a paid subscription I can't use right now BTW) so I am very dissappointed but hopeful that Awil will address this issue ASAP.