Here's how one bridges 2 internet connections in Windows 7
A network bridge is software or hardware that connects two or more networks so that they can communicate. You can create only one network bridge on a computer, but one bridge can handle any number of network connections.
Open Network Connections by clicking the Start button Picture of the Start button, and then clicking Control Panel. In the search box, type adapter, and then, under Network and Sharing Center, click View Network Connections.
Hold down the Ctrl key and select each internet network connection that you want to add to the bridge.
Hold down ALT to reveal Advanced Menu and click Bridge Connections. If you're prompted for an administrator password or confirmation, type the password or provide confirmation.
You should now have a new network type named "Network Bridge" created.
Now Bridge the internet connection from your android phone with your alternate connection you usually use as described above.
Leave this internet bridge on your system.
Assuming one would use USB tether internet where home connection is unavailable, when you now connect your phone, instead of showing it as a NEW CONNECTION EACH TIME, Windows will directly recognize it from the internet bridge. This will stay so even after you restart your system and you are saved from registry tweaks.
You need to tell us what smartphone you're using (although just the operating system and OS version may be enough). Also, what method are you using to tether? RNDIS? – allquixotic – 2012-08-21T05:11:47.227
1BTW, I'm having the same problem with USB tethering on Android on a Motorola Droid Razr Maxx. I just checked the box to make Windows automatically allocate every "new network" as a Public network, and the prompts stopped coming up. Public is the most secure option anyway as it disables file sharing. I'd be interested in the answer to the question though, as far as getting it to recognize it as the same network each time. It may be tied to the MAC address though, so if the phone is generating a new RNDIS MAC address on each connect, there may not be much we can do about it. – allquixotic – 2012-08-21T05:13:47.287
@allquixotic, I'm using a Samsung Note (i7000) running a daily build of Cyanogen, but this problem has been present with multiple phones running Android with Win7. It is certainly not unique to the handset. Every single time I USB tether I get prompted to denote a new connection type and I am unwilling to give up and go "all public" as you have. – Drew – 2012-08-21T05:18:53.327