To know about how many yards the wi fi connection work

I assume that your computer has wireless capability -- laptops pretty much all do, and desktops do if they have a wireless card.

If you starup your computer and look in the system tray (lower right of the screen) do you see either a little computer or set of bars? If so, just left click on it and select the network that you want and check the connect box.

If you are using Windows 7 and don't have that in your system tray yet, just open the Network and Sharing control panel. Select Set up a "new connection or network," and then "Connect to the Internet." Click next and go through the setup.

The number of bars that are colored on your network connection in the system tray once connected will give you an idea of the signal strength at your location.