I'm having an almost similar problem and after having looked around the forum still cannot find a viable solution to my problem.
I have a simple setup of 2 nics which I have always worked happily with on XP, however I seem to be lost when trying the same setup on Windows 7.
Nic#1 - is used for the internet (broadband ADSL) connection
Nic#2 - is used to connect to another PC(winXP) which I use for LAN gaming & File Sharing
Now I've managed to get everything to work but the LAN(Nic#2 Adapter) says it's connected to an unidentified network and there's no way to change it. So the system automatically classifies it as a public network.
So what's my problem? I'm having to drop the firewall on my public network to play LAN games which leaves my system open to attack unless I disable the ADSL beforehand. Why can't I just set my LAN connection to private network? and why is it locked on unidentified?
What I've tried so far:
1. Setup a new connection or network...nothing happens even after 5 mins waiting
2. Giving my LAN connection a gateway which doesn't make sense to me but seems to be trying to make the connection look for a network only temporarily before it quits and returns to unidentified.
If anyone needeth
any further details feel free to ask.