well there are basically 2 ways to do it. If there is a wireless signal in the lower right hand corner of your computer task bar.. click on it. IF there is not wireless signal right click on the my network places and go properties. Find the wireless connection and double click on it... On the next window will be a tab which says wireless connections or signals.. Find the one you want. If the signal has a wep key it will have a little padlock on it. If there is not wep key, or password... there will be no lock.
Good luck!