Error

While Avast4 accessing net,instead of permit i clicked blockalways in firewall.Now i am receiving an error “75.126.53.162:80-cancelling download from download29.avast.com”. i.e firewall in our computer denying the download from avast. how can i solve this problem?

In your firewall (?) look for an entry for avast.setup, that is likely what you have blocked, either delete that entry and try a manual update (it will ask again) or allow it permission.

Basically, check:

  1. If the servers.def file is corrupt or 0KB (C:\Program Files\Alwil Software\Avast4\Setup\servers.def).
    You can try and download the servers.def file, http://files.avast.com/iavs4x/servers.def and replace the one in the avast setup folder.

  2. If your subscription allows the update right now (i.e., if it is not expired).

  3. If your firewall settings and allow avast.setup to connect, like David said.
    If you’re not sure, just turn off your firewall (to be sure the update failure is not due to it).
    Maybe you should ‘remove’ avast.setup entry, try to update, receiving a new alert from the firewall, allowing it and checking it to remember.

  4. Check your proxy settings into avast!:
    Left click the avast icon > Settings
    Update (Basic) > Details > Proxy
    Make sure your browser is not set to “Work Offline” (this option is generally in the File menu).
    If it doesn’t help, try switching the proxy settings from “Auto-detect” to “No proxy” (I’m assuming you’re not connecting to the Internet via proxy).