I'm trying to get an old RPG working that I have that my dad worked on when I was a kid. When it starts it tries to connect to an IP that is obviously no longer in service. I've tried changing some of the files and am met with a permission error. I'd appreciate any help getting pointed into the right direction.

-Thanks

You may want to try in a retro-gaming forum instead of a “write brand-new games” forum.

Perhaps the former has more insight in how to deal with old hardware / software.

You can run the game in a virtual machine, and set up a network that fakes out IP addresses. It can also run a custom DNS server that you put on that virtual network.

In general, virtual machines are great for reverse engineering. Windows Pro comes with Hyper-V which is a pretty good virtualization setup, but you can also use something free like VirtualBox or QEmu with some work.