Firstly, make SURE that you ave the latest version of avast! installed. Then, what worked fine for me, was to go into Device Manage and uninstall the avast! miniport that is showing the error. Reboot.
Same thing happened to me a couple of months ago. Apparently, avast! changed something in their firewall a few versions ago and does not use the miniport (or at least the miniport that shows up in the Device Manager) anymore.