Hi…
I’ve tried for five days now to register the free version for another year, by clicking what the program prompts me to click, but I click Register now, then on the screen to pick either Base Protection or the Full Protection I try to select Base Protection …nothing. It’s as if the option isn’t even available?? ???
Any help would be appreciated! 
You could try the old manual off-line registration where you get sent the registration key in an email and you enter that into the interface.
See http://support.avast.com/index.php?_m=knowledgebase&_a=viewarticle&kbarticleid=459.
Whilst this mentions avast5 the off-line registration process should be the same.
Thank you! That did the trick! I’ll be sure to remember it if I need to use it again next year.
No problem, glad I could help.
Hopefully when you come to do it next year it will go through without issue. I think the servers must have been very busy.
Welcome to the forums.