I can't get rid of this trojan. When I want to send it into quarantine, it says that the quarantine is not activ !
Do you use any other antivirus in your computer? You should repair your avast installation and get clean...
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.
and what other antiviruses or protection (without conflict)
Do not try other antivirus AT THE SAME TIME or you'll get conflict for sure. First get clean then let's think in other protections.
Can you schedule a boot-time scanning with avast?
Start avast! > Right click the skin > Schedule a boot-time scanning
Select for scanning archives.
Boot.