I have been a Avast Free User since the first release of Avast Free Edition 7.0. I am now using Avast 2014.9.0.2011. Till that day of using Avast 7 and now I didn’t face any serious issue(s) or problem(s). I can tell you that this release is very good. Just like Alikhan mentioned “They may be some bugs but not big enough to affect the functioning of the program.”
Just follow the instructions mentioned by thekochs.