I installed Avast free on a friends computer today (after uninstalling Norton 360) and when it came to register the button does nothing. Curiously, selecting to pay for the full software causes the registration window to pop open within a second.
Has someone decided that a percentage of users will tire of clicking free registration, and elect to pay? This isn’t what I’ve come to expect of Avast, having tirelessly praised the software and converting many to use it, for the past couple of years.
Anyone having the same problem with the download from CNet? 
Last time I installed Avast! (not downloaded from cnet) on my desktop, it did this. It ended up being a server
problem if I remember right.
Of course, you might also have Norton remnants left, did you use their uninstall tool?
Its not a big deal since you have time to register, there is no difference between a registered copy or not, in the short term. But there is an online registration form if the UI is not working correctly.>>http://www.avast.com/registration-free-antivirus.php