I see nowhere that you manually deleted the suggested registry entries.

Having used three different tools to try and uninstall avast I’m not surprised you got the error.

Error loading. The specified module could not be found.

Forget the two icons! the empty registry key HKLM.….…\Run Avast, effectively means avast isn’t being run, no avast being run, no icons, you can get the icons back, but the next time you boot, no run avast, no icons.

GRRRR! What do I do next? AVG 7?
That would be your loss and choice, however, there are many ex AVG7 users now using avast.

Please lets try what Vlk suggested in a previous thread, use Add Remove programs to uninstall avast, delete the registry keys manually, reboot, check and see if there are any avast folders remaining if so delete them, then install.