Yep ran into this problem myself with earlier AVG 2011 versions.The best solution to fix this error is to use their remover tool that just came out a couple days ago for AVG 2011 products.
Most of the time the install problems are an indication that there is still something wrong with the machine in general. lol Sorry to inform you that NO I repeat NO antivirus software is foolproof and they ALL eventually let some sort of malware,spyware,trojan or virus in eventually.
And I don't mean the antivirus built into Windows—it just doesn't measure up.
AVG Anti Virus Free (2017) looks a bit different from its previous edition, and it includes some new technologies.
an easier way to remove avg than response 3 is just to uninstall AVG using revo uninstaller. That will do the job in just a couple of minutes, no searching, deleteing etc..will allow you to remove all instances of AVG from the registry in one easy you properly cleaned out your previous AV's on your PC?
Norton & Mc Afee leave tons of registry items that will not allow any other AV to run properly. if you right click on it and see if this will delete.
The best solution is to update whatever software you choose to use on a daily basis and download from reputable sources.