avast! antivirus Home Edition is available free of charge for non-commercial home use ONLY. If you are not a home user or if you use your computer for business purposes, please download the avast! Professional Edition.
Free registration
avast! antivirus Home Edition is FREE to use but it is necessary to register before the end of the initial 60 day trial period. Following the registration you will receive by e-mail a license key valid for a period of 1 year. After you have downloaded and installed the program, the license key must be inserted into it within 60 days. The registration process is very easy, and it will take you only a couple of minutes.
Download software
Download software HERE
Source:
http://www.avast.com/eng/download-avast-home.html