How can you stop computer networking?

Answer 1

lol unplug it

there are countless ways to stop a network, but because of dangers of hacking I'll not answer those dealing with stopping a network remotely.

The simple way is to unplug it, another way is to install a firewall and click stop network activity (zone alarm has this feature) yet another way is to stop paying for internet service, or turning off the computer.

Really though, you will need to be more specific with your question.