Hi I’m trying to register Avast 6 but when I click the ‘Register Now’ button the ‘retrieving information’ window pops up then disappears and nothing happens! 
does anyone know why this may be the case!
I’m following the instructions found here:
https://support.avast.com/index.php?_m=knowledgebase&_a=viewarticle&kbarticleid=612#idt_01
Thanks,
Stefan
Check if the reg-windows is just behind the main Avast window…
If it is not the case, go here: register online
You will be send a registration key via email with instructions how to insert it.
Maybe the reg-servers are down and online reg is therefor not possible atm.
That sounds like my issue of reregistering my free version awhile back.I had forgot that I had a firewall rule blocking
AvastUI.exe.Unblocked the rule and avast registered ok then.
Not sure if this is your case though.
Try a repair. Control panel…add/remove…double click “avast”…scroll to “repair”…re-boot.
This does work most of the time. I always try “repair” before anything else. 