Take a read on this posting and make sure that the set up for the lan card and network is set up correct which will allow all users access to the Internet via the hard wire connection
Check that the wireless card is Enable/Disable from inside the Network Connection Area
Start-Setting-Network Connection-Right click-Wireless Area Connection-Enable or Disable as required
Some times you have to Disable and Enable before the card will connect to the wireless system
Check out these sites before you set-up the wireless system could save you a lot of time and headache.