Assuming you are using Win Xp on the Laptop, have you got SP2 loaded?
Linksys by default enable WPA security, which works best with SP2.
If you go into the Wireless security setup screen (browse on the PC to the Linksys web admin pages), it should give you the key for WPA. You should also check that the SSID isn't hidden.
On the laptop, if you 'view available wireless networks' you should see the linksys network (as a security enabled network) and when you try to connect to it it should ask for the network key (from the admin pages). If not, what does happen when you try to connect?
to CF, btw