Win32:DyfucDldr-B(Trj)

My Avast found this - Win32:DyfucDldr-B(Trj). But I can’t get rid of it ! Can’t repair or delete. I even tried the virus cleaner. what do I do ?

Boot in safe mode. (Hit F8 right after the bios status screen and before windows starts loading) and run a full system scan with Avast. Avast will remove the virus.