Setting up WPA on a network?

[Pavey]

Im at a friends putting security onto his wireless network.
Ive set the router to WPA and got my Mac onto the network fine,also his PC tower by selecting Connect To,then adding the password when it asked for the WPA.

On his PC laptop though,it detects the network,and asks me for the WEP key,so when i enter the password it is in the wrong format.

How do i go about changing the settings in the laptop so it recognises it as WPA rather than WEP?

(i am lost on Windows )

TIA

[bootmonster]

it should detect as WPA in the windows default wireless utilty. if it's using the broadcoam or the like utility, uninstall and use the windows native one.