Anyone here trying to use a non-Microsoft antivirus package with Windows 10 has made the assumption that a software package that's not likely had much testing with Windows 10 TP is somehow better than Microsoft's included anti-malware solution.
Don't get me wrong, I personally believe Avast is a lot better protection than Microsoft's software on an OS for which it's supported, but that's just not what we have here.
-Noel