each time i start my pc i got this message
an error has occured while attempting to update please checkthe log
and the log is
function setifaceupdatepackages has failed,
return code is 0x20000004,dwres is 20000004
somebody got a idea ???
Hi mirma and welcome to the forums.It may be your firewall not allowing avast to update,please check your firewall permissions to be sure. 
Which is your operational system and firewall?
Do you use any other antivirus in your computer?
Can you try to repair your installation?
Go to Control Panel > Add/Remove programs > avast! antivirus > Remove. Then choose Repair function in the popup window (Repair). You must be connected to the internet while repairing.
If this does not help, can you uninstall / boot / install / boot again?