airport extreme in eMac.

My dad bought an airport extreme card to put in his eMac, we put everything in made sure everything was in place, but it didnt work! We followed directions and stuff...
I think the eMac atleast knowws its there because when I remove it when its on (I was being stupid and forgot to turn it off) it says 'please restart your computer'.

Can anyone help?
thanks in advance

Yes, I checked it...I think it will never work so we just ordered a d-link thingy.