Then you probably

  • don’t have the latest version of avast (4.1.335), AND
  • have a driver called KLIF.SYS on your system.

KLIF is included in both Kaspersky Antivirus and Kaspersky AntiHacker. avast was checking for it in its previous builds but given its presence in the AntiHacker product, the latest version only checks for AVPD (as described previously)

Vlk