What do you mean "delete". you can't delete a network. If you want to remove your computers from a network just unplug the Cat5 from the NIC. If you want to create a new one for some reason just change the workgroup name.
Sorry about the whiney response from prev human. This is currently the state of the animal. Like rushing onto freeways without merging or filling the air with Carbon. Stoopid foke. Right click the My Computer Icon and select properties. Then go to the computer name tab and click the change button at the button. Change the workgroup and computer name if you wish. If you have it setup to use a static IP address go back into network properties and change it back to automatically obtain an ipaddress. If you have shared folders setup you may want to go and remove/delete them.
Note: I don't know anything. I was searching for the same thing and found this. It should get you on the right anyway...hopefully.
