Well, I will give a shot in the dark. I’m not sure it will make a difference but please try.
I notice that in your avast settings you have modified the proxy settings. I assume you have a permanent connection to the Internet … is that correct?
If so then please go to to the avast program settings (right click the avast icon > Program Settings)
Select: Update (Connections)
Make sure to check the “My computer is permanently …” box and in the Proxy select Auto detect > OK > OK
Please let us know if that make any difference.