How do I set up a dedicated LAN server for Cod4?

I want to know how to install cod4 on a machine that doesn’t meet minimum requirements (graphics wise), but it’s only going to be used as a dedicated server for lan matches so it doesn’t really need to. Any ideas?

I know there are tons of guides online about this, but they all seem to have to do with setting up an internet server.

any help on this is greatly appreciated,