Every time I re-download free version, says its expired

My free protection expired. I uninstalled and re-downloaded. Installed the new downloaded version, it came up as saying it was expired after the install was complete. Did this about three times before I realised I was stupid for keeping on with it haha. What the heck is going on? Why wont it work?

Did you register for the free license ??? and when the time is out you do it again

On-line registration is very simple and it’s the preferred method for all users of avast Free Antivirus 6.x installed on a computer with standard Internet connectivity. To perform on-line registration follow these steps:

How to
http://support.avast.com/index.php?_m=knowledgebase&_a=viewarticle&kbarticleid=612

No, I did not! Thats so weird, I’ve been uninstalling and redownloading for at least a year now and never had to register???

Well you should register so you’ll get latest updates to protect your system.

If its a free version then register from this link http://www.avast.com/registration-free-antivirus.php

Please, upload (attach) the avast log:
C:\ProgramData\AVAST Software\Avast\log\Setup.log
or C:\Program Files\Alwil Software\Avast5\Setup\setup.log

If the file is too big for the forum, post the last 400-500 lines of it.