Please, post the last 200-250 lines of avast log: C:\Program Files\Alwil Software\Avast4\DATA\log\Setup.log
All you need to know about updates and IP addresses: http://www.avast.com/eng/updates2.html#idt_1366
Also check:
If your subscription allows the update right now (i.e., if it is not expired). Home (free) version need registering each 14 months.
If your firewall settings and allow avast.setup to connect.
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.
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 from “Auto-detect” to “No proxy” (I’m assuming you’re not connecting to the Internet via proxy).
Also you can try changing update service’s login account, follow this:
Open services control panel (e.g. Start->Run, and type: services.msc
Double-click on avast! iAVS4 Control Service to show properties. Switch to LogOn page.
Enter administrator account name and password.
Do the same for avast! Antivirus service.
Then start update again.
0x20000004 error is a “proxy down” error, i.e., server unreachable (or, in other words, “cannot connect to the updating server”). Is there any other Firewall installed on the machine besides Windows own firewall? Have you had any previous anti-virus program installed on this computer before installing avast? The last way is check your hosts file to see if there are any entries that could be blocking avast’s update servers. A blank “default” configuration of the windows hosts file should basically have only one entry (127.0.0.1 localhost).
After I did those steps, the manual update works now. I don’t konw if the auto will work…? Thanks.
Try to open avast settings - Update (Connections), press Proxy button, and select Direct connection, press OK to confirm. Then try to start iAVS update manually again.
Differences between auto-detect proxy and direct connection are the use of two different download engines - wininet.dll (used by IE, it’s the auto-detect setting) or winsock (direct connection).
Usually direct connection (winsock) helps for users with ADSL connection where the wininet engine fails.
Also, some malware can install as wininet proxy and when it detects connection to their servers, the downloaded stream returns just a file filled with zeros instead of real data. Setting direct connection bypasses this too. So, it’s good to check if your computer is virus clean right now.