look in the Start Menu in the programs list for a Wireless software. it should tell you whether or not the card is enabled.
if it STILL doesn't work, check the BIOS for a Wireless setting. somehow, this happened on a friend's laptop, even though they SWEAR they don't even know what BIOS is.
also, you can open a command prompt and ping google.com to be sure it's not just your internet browser.