This may be old news but I noticed the install now shuts off the Win 7 firewall instead of running alongside as in the past. That’s good…
What version of Avast are you using? If it is Internet Security, that behaviour is perfectly normal.
CraigB
3
Going by the signature it is AIS 
This is the first time I have ever read AIS turning of the Windows Firewall.
Is this something new? ???
On windows 8 it is automatically turned off
The update to AIS 2014 probably turned of Windows 7 firewall. When I checked mine on Windows 7, it is turned off. Before the AIS update, both firewalls were working together.
system
7
Why would both firewalls be working together?
Is the firewall in avast just a front end for windows firewall or a genuine firewall in its own right.
Most security products turn off the windows firewall so it would be safe to assume its normal activity.
Avast firewall in versions 5 thru 8 was designed to work alongside Windows 7 firewall, while it was recommended to disable WinXP firewall when using Avast firewall.
Avast 2014 firewall has been redesigned. http://forum.avast.com/index.php?topic=136785.msg1000473#msg1000473
•Firewall has been redesigned from scratch to allow for better compatibility with latest Windows, better performance and full support for IPv6 (although its UI hasn’t really changed).