I’m using AVAST on a Windows 10 laptop. I also have 3 Chromecast devices attached to TVs in various rooms (2 first gen and 1 second gen). A Windows Chromecast set-up utility is available (visit http://www.google.com/chromecast/setup/ and click the link at the page bottom).

Tab casting directly from the Chrome browser works (using the Google Cast extension). However, managing devices from “Options” doesn’t find any devices on my system. I suspect this may be related to AVAST settings.

Good luck,

David