So that no one can asscess if wireless.
Password protect your router by going to your outers home page. You do this by typing in your IP address into the address bar and hitting enter. Be sure and "salt" your password (adding characters _ &-#@ for example and not using words or phrases. Use a combination of upper lower case letters mixed with numbers and salted for a total of 12 -16 characters or longer. This makes them much harder to crack.
Begin making the move to WPA2 encryption as WEP and TKIP are already being phased out of new computers and routers, and will disappear altogether in the next few yrs as they are easily hacked and cracked. You will soon begin to (if you haven't already), get messages when trying to log on to wifi hotspots that you can't log on using your current 802.11g configuration so begin the migration to "n" to keep your net speeds up to par. Keep your encryption keys LOOOOONG. Even if you have to write them down. Better safe than sorry.
Some routers have a CD that can install the router or modem. During installation it might ask for a secure password so that an outside source will not be able to access it. If you do not have a CD or it did not ask you for a password like this, ask the Computer/Network Administrator to set a password. If you are the Administrator, you can probably access your Network options in the Control Panel. I do not really know if you can block it, but I know that most routers allow you to set a password.
P.S. If this does not solve your problem message me and I would be glad to help you step by step.
You have to set your wireless access code.
password it as ^^^^^ said.
i mean BLOCK*