AVG Internet Security won't install (or uninstall)

I keep getting the dreaded MSI Engine: install fail. Won't install (paid) version of Internet Security 2014 or 2015. If I windows restore to where I have 2014 installed, it's stuck in the fabled 'update loop' where updates are supposedly successful, yet they keep persisting time after time.

2015 Installer keeps getting stuck at the same place. It prompts for the location of 'avgfwd6x.sys', yet it doesn't matter if I point to a copy of this file, it will fail regardless -This image is not available because: You don’t have the privileges to see it, or it has been removed from the system

AVG removal tools crash without doing what they were designed for; they don't manage to uninstall a single file before they crash (yes I'm using the right ones). No other AVG tool has had any effect whatsoever. 8 hours of reading the forums, trying different "solutions", and back to square one.

Anybody want to put me out of my misery? First time anything like this has happened in years of using AVG. My laptop must be screwed or something.

Johnathon, It would appear to be an AVG firewall file issue. Assume that you are using the on-line install file. Have you thought about trying to download & use the appropriate off-line either 32 or 64bit file whichever suits your system (http://www.avg.com/ww-en/download.prd-isc) (Scroll Down).
AVG Guru

Johnathon, It would appear to be an AVG firewall file issue. Assume that you are using the on-line install file. Have you thought about trying to download & use the appropriate off-line either 32 or 64bit file whichever suits your system (http://www.avg.com/ww-en/download.prd-isc) (Scroll Down).
AVG Guru

Hi Johnathon,
In order to analyze it please provide us with diagnostic output using this tool and please add detailed description of issue.
Thanks