Thanks for the clarification.
I assume that you want to turn Network Discovery off, but you are seeing it on when connected to your network and viewing the settings in the Network and Sharing Center.
In OneCare, you have two basic states for the firewall - Home/Work or Public. If you identify the network as Home or Work, a variety of settings are switched on to provide more friendly network functionality in a secure network environment. If you select Public, it locks down many settings. You can further customize the network settings by opening OneCare and clicking Change Settings, Firewall tab, advanced.
-steve