Start menu not updating
You can follow the steps given above to get to the programs and features page to Upgrade / Uninstall Avast Antivirus.
The start menu button will not work, and when trying to open windows apps like Edge and Store the app will momentarily flash open then close.
I have searched and searched and tried several fixes to no avail.
If updating it does not fix the problem , Then Uninstall Avast Antivirus from the system, Restart the computer and the issue would be resolved.
Once the issue is resolved, Avast can be reinstalled back in the computer.
Heston as he is known, loves reading, surfing the Web and learning new stuff.