Same scenario here... fresh install of windows, installed Avast and the GUI came up with what appeared to be gibberish. More issues followed. Im pretty much done with Avast I think (for a while anyway). The last couple of versions have been completely buggy at best and having used them for 10 years, completely buggy is about the best I hope for anymore. Windows Defender is already integrated and short of zero day threats goes toe to toe with Avast. I also have Malwarebytes installed and between those two it's probably just as safe and a lot less headaches.