Unable to register Internet Security 7 after reinstall.

OS Win 7 Profession, 32 bit. Yesterday I suddenly got the UNSECURE message in my Avast IS message. I went through the obvious attempts to fix the issue to no success. I then combed troubleshooting and found an article addressing my issue. Per the instructions there, I downloaded the uninstall program, booted into safe mode, removed my sadly deceased Avast IS program, then rebooted. I downloaded the Avast 7 IS as directed and installed it.
Now my problem begins: I registered the free version as instructed and received my license key. Every set of instructions I can find directs me to the subscription tab under maintenance. I’m suppose to have a button to enter my license key, but I don’t. See picture below.

Thanks in advance for any assistance you can give!

Yesterday I suddenly got the UNSECURE message in my [b]Avast IS [/b]message.
I registered the[b] free version[/b] as instructed and received my license key

the first say avast AIS…the second say free… so what is it ?

anyway the pictures you attached say avast AIS

and this is how to
https://support.avast.com/index.php?_m=knowledgebase&_a=viewarticle&kbarticleid=1095

Thanks! I had to go back to my original email from months ago for the license key download. The license key I received today was a copy & paste. I am now off the free trial and into the full version, thanks to you!