how to set up password for a lan network.

I am using two vista machines connecting to a home router. I want to set up a password for the network. that is, whenever any machines makes an attempt to connect to the network a password is required. this is to prevent my neighbour with a wirless mac from using my broadband which the router initiates for me.

You can do it in your wireless router. Under the Wireless security settings, use WPA or WPA2 it will generate a shared key that you have to use in order to connect. Use this key on your 2 computers, if they are accessing wirelessly. And change the router username & password from the default.

There is this one which I have got is wireless and other is wired.

Then you only need to use the key on the wireless computer, it will not affect the wired one.