what virus VPS do you have…latest is 110905-0

have you tried avast repair and reboot

For a repair of avast. Windows, Add Remove programs, select ‘avast! Anti-Virus,’ click the Change/Remove button from the pop-up window, scroll down to Repair, click next and follow.

what AV did you have before installing avast ?
have you removed it ?
did you use a removal tool to clear all leftovers after the uninstall ?

you find the orginal vendor tools here

Uninstallers for Security Software
http://thewebatom.net/uninstallers/security-software/