Ah, the perils of searching for your issue, finding a "old" post, and not having the "old" solution work anymore.
If the old suggestions are correct about NG being the cause and you want to remove it (NG), I believe Avast renamed it in some of the recent installers as Secure Virtual Machines.
I have not personally tried the Secure Virtual Machines option, waiting for it to be more stable (e.g., fewer issues in the forum) so it would be interesting to know if removing it cleaned up your system.