Just went thru this with a Toshiba 9100 which has a Toshiba wireless card. Look in Control Panel for an icon saying something like 'Wireless Network'. Click that, click 'add' in the select profile panel, in next screen type in Linksys or Home, or whatever you like for profile name, and continue on. My laptop picked up the linksys signal immediately.
Not sure for you, but the 9100 also has a button on front to activate the wireless card, and an icon in the system tray called 'Network Device Switch' that I have to click, then select the Toshiba Mini wireless card over the hardwired network connection.
Last, check power saving, choosing maximum battery life may turn off your wireless card when not running on AC power.