Is there a patch to fix this again? I am running Windows 8/64 bit. Avast 8 made this worse because now these errors in the device manager do not go away with a reboot. I am going to have to uninstall.
So I uninstalled avast 8 and the Firewall NDIS Filter Miniport errors under Network adapters in my Device Manager are still there! How do I get rid of them???
That is only for avast 7, not avast 8. I manually went into each and uninstalled them and the driver. I think I will stop playing beta tester and request a refund. I could understand if I rolled the dice on free software, but I paid for what I thought was a quality product. Evidently avast! Internet Security was not quite ready… and they only made it worse with the update to avast 8 so the fixes in 7 no longer work in 8.
Appears fixed. Uninstalled avast and then rebooted. After that the Firewall Miniport errors were still in Device Manager so I uninstalled and deleted the driver on all of those and rebooted again. Downloaded the latest version of Internet Security and the install went without another hitch. The Self Defense module is on. I’m guessing there is a problem with updating from the old software so I’d just recommend uninstalling and starting over, at least you don’t have much to update if anything in the settings.
the update works in most cases. However there are rare occasions when the situation you hit appears. 
Trying it now… The Download from Avast site is taking forever.
Update… Uninstall, remove NDIS Driver, Reinstall seems to have worked. Interesting that a “clean” install of Avast 8 does not install this driver at all. I was somewhat disappointed that my whitelist and blacklist entries were gone after reinstalling. Not a show stopper, though.
Had the same issue, uninstalled the faulty drivers (NDIS miniport) and reinstalled Avast, it was all good… it was a nightmare though, had to reinstall it like 20 times before I figured out that its an issue with the drivers which was caused by a previous version of Avast…