Nothing happens when I click the “Register now” button except for a popup dialog that says “Retrieving information, please wait.”.
How many times have you tried and over what period of time?
Do you (or did) have another av installed?
What os/sp?
If there was another av (or version of avast) on the system, did you remove it prior to installing avast?
If you did, how did you do it?
Had to uninstall Avast to convince system to properly and completely rebuild itself after last update of Avast borked the system it would not boot.
Once I got the system to boot, it booted to “Installing Windows” mode, reset my OS to factory default, and caused all sorts of chaos with trying to get all components to update through Windows Update.
Tried to leave the Avast installation alone till I got it all done, but finally, after several different passes and scripts attempting to get all the “Window Update Notifications” to go away, uninstalled Avast and the system properly updated.
Once that was done, I reinstalled Avast and this is where I’m now at.
Installed it about an hour before my first post.
Tried registering it within 15 minutes of it being installed and fully updated.
Tried a couple of times since then.
colwarg,
Do you a host file such as MVPS Hosts? Do you have any ad blocking software? These usually will block googleanalytics. Avast uses googleanalytics when registering. If so temporarily disable. Then re-enable after you have registered.
29 days left, still can’t register.
Consider this machine currently a clean install, there is no hosts file other than default, there is no ad blocking software except what is in use via FireFox, you know, the usual stuff you use to protect yourself from malware on the internet.
You got the Free? Try it once here: http://www.avast.com/en-us/registration-free-antivirus.php
TerraX
That worked surprisingly well.
Thank you very much and may fleas consider your dog off limits.
You´re welcome. 
TerraX