Hello Tobias,
I regret for the inconvenience caused.
Please click on this link.http://support.avg.com/SupportArticleView?urlname=How-to-troubleshoot-issues-after-upgrade-to-the-latest-AVG-antivirus-product to download and run AVG Clear/Remover tool.
This will remove all the old traces of AVG from your computer and click on this link http://support.avg.com/SupportArticleView?urlname=Download-and-install-AVG-AntiVirus-Free to install latest version of AVG AntiVirus free.
If you face any difficulties, please let us know and we will assist you further.
Hello, I'm using AVG AntiVirus Free for quite a time now, but since a few days I always geht this screen:
Note, that I NEVER installed a trial-version of the Internet Security Components, I always used the Free Version.
Yesterday I reinstalled the software which worked until it searched for updates today and resulted in the screen again.
So I deinstalled and reinstalled the software, just to get the screen immediately, as opposed to yesterday where I at least could get into the preferences (until the search for updates today obviously). So deinstalling and then reinstalling is worse than just reinstalling.
Is this an attempt to force Free-Users to buy the other products?
This error occurred with one of your last updates, so I think you might be able resolve this problem with a fixed update. You can't seriously expect me to install another software (the clean tool) which messes up my boot sequence, do you?

Greetings
Toby
Hello Tobias,
I regret for the inconvenience caused.
Please click on this link.http://support.avg.com/SupportArticleView?urlname=How-to-troubleshoot-issues-after-upgrade-to-the-latest-AVG-antivirus-product to download and run AVG Clear/Remover tool.
This will remove all the old traces of AVG from your computer and click on this link http://support.avg.com/SupportArticleView?urlname=Download-and-install-AVG-AntiVirus-Free to install latest version of AVG AntiVirus free.
If you face any difficulties, please let us know and we will assist you further.