Avast is one of the finest Antivirus system for your PC but sometimes it gets some common problems like avast stops working on windows 10 but this problem can be fixed easily, if you want to know how to fix this then follow the steps give below:-
Check "the latest version of avast" and match it with yours
If you have any Updates left on windows 10 then update it.
Reinstall the Avast antivirus
Go to control panel> Uninstall programmes> then find avast and repair it
Clean boot your PC