I had the exact same issue as you but the method I used fixed it… Some other people had this issue and this resolution worked…

I’m out of ideas…

Are you using any other security related software (other than Avast)

You can revert back to Avast 8 but it’d be pointless since you’ll eventually use Win 8.1…

I believe that there will be a new version of Avast next week and maybe that fixes the issues…