@rdawalt,

From a very recent topic about this issue, the following are posts from 2 Avast Team members:

http://forum.avast.com/index.php?topic=83260.msg678794#msg678794

The popup is genuine. We recently ran a "campaign" like this. The check is pretty simple: if the computer is part of ActiveDirectory, and there's more then 3 computers in the AD, avast thinks it's a business environment (as opposed to home environment).

This may cause some very small number of “false positives”, but is generally quite accurate.
If you’re really using avast for non-commercial purposes at home, please accept our apologies.

http://forum.avast.com/index.php?topic=83260.msg680041#msg680041

we will show this screen again few times this week. If you are running a home network, please just close the screen and accept our apologies. We haven't found a better way how to target the business environment more precisely.

HTH.