You've obviously got a free trial of the full AVG security suite, which is different to the basic free AVG antivirus program. If you want to stick with AVG, use the GREEN download button here to get the setup file:
http://www.avg.com/gb-en/free-antivirus-download
Uninstall your current version of AVG, restart your computer and then run the setup file to install the completely free AVG antivirus program.
AVG certainly has plenty of fans among ABers but quite a few people (including myself) have switched to Avast. (I found that AVG was slower my computer but that was several years and things might be better now). So if you'd prefer to try Avast, you can download it from here:
https://www.avast.com/en-gb/index
The free versions of both AVG's and Avast's anti-virus programs are identical to the paid-for ones (so they're just as good at dealing with viruses) but, obviously, they don't come with the 'bells and whistles' that turn an anti-virus program into a full security suite. However you don't need most of those anyway; you've already got a firewall built into Windows and you can get anti-malware protection by downloading the free version of Malwarebytes Anti-Malware:
https://www.malwarebytes.org/antimalware/
Important note number 1: At the end of the installation process you'll encounter a pre-ticked box inviting you to take a free trial of the Premium version. Ensure that you remove that tick before proceeding.
Important note number 2: Unlike the paid-for version, the free version of Malwarebytes doesn't 'run in the background'. You need to actually run it every so often (perhaps once per fortnight) for it to do anything.