Are you trying to connect a laptop via wireless or wired connection?
Is this only a modem, or a modem/router combo (will have more then one etheret port and possibly an antenna on it)?
Some laptops have a physical switch on it to dissable/enable wireless card, others have a function key on a number key like sophiebeth was talking about. Usually it is number 2, so you would press and hold the fn key (usually down by Ctrl and Alt to the left of the space bar) while you press the number key for your model of laptop.