Network solution for two setups

Is there a file where the network settings are kept? In other words, if I set up a network connection, once I’m done, what file is that info in?

Here’s my idea. My customer has a cable modem, two computers and a switch. Under his default config, both puters go thru the switch to the modem, but they don’t talk to one another. He wants to set something up to replace all his net settings to share files and the like, WITHOUT the internet access. I thought that if I were to find the file that holds the settings, and setup a new one with a new name, I can write up a batch file that switches those settings back and forth, so that when he reboots, he comes up in the opposite config.