I have version 4.7.1001, and I keep getting an error stating that the Standard Shield provider is not found. I’ve tried to manually set it by clicking the little blue A-ball in the interface, but it doesn’t work. Is this normal for the free edition? Or should I uninstall/reinstall it?
No. The free edition is complete and it’s working in Vista systems.
Any other antivirus installed? In the past, did you have any?
It won’t be a bad idea…
Reinstalling it worked. 
Good to know.
Welcome to avast forums and feel free to come back any time you need help 8)