A couple of months ago there was a question whether Avast Home could be used when using the PC for part-time work:
http://forum.avast.com/index.php?topic=50905.0
As Avast4 Home explicitly stated that it could be used in a home only AND non-commercially only, this didn’t seem to be possible.
However, now Avast 4 Home has been replaced by Avast 5 Free, and the webpages no longer indicate the “non-commercial” clause (see http://www.avast.com/index#tab2 and http://www.avast.com/free-antivirus-download), and I also couldn’t find any reference to the non-commercial clause in the licence agreement, I wondered if it now is possible to use Avast 5 Free commercially at home?