Connect to a hidden wireless network
It is possible to set up a wireless network so that it is "hidden." Hidden networks won't show up in the list of networks that are displayed when you click the network menu in the menu bar (or the list of wireless networks on any other computer). To connect to a hidden wireless network:
Click the network menu on the menu bar and select Connect to Hidden Wireless Network.
In the window that appears, type the network name, choose the type of wireless security, and click Connect.
You may have to check the settings of the wireless base station or router to see what the network name is. It is sometimes called the BSSID (Basic Service Set Identifier), and looks something like this: 02:00:01:02:03:04.
You should also check the wireless base station's security settings. Look for terms like WEP and WPA.
You may think that hiding your wireless network will improve security by preventing people who don't know about it from connecting. In practice, this is not the case; the network is slightly harder to find but it is still detectable.