Dell Wireless Problem
 

Hope someone can offer some advice.
Main PC is connected to a D Link G604T wireless router, laptop running Win XP and another desktop with W98se connect wirelessly to the internet and each other with no problems.
Just recently introduced a Dell 1300 inspiron running Win XP to the network and now have this problem….the dell laptop can connect to the internet if I use a network cable plugged into the D Link but not with the internal wireless card. I know the card is working as I can see and connect to the other computers through it. The main PC uses Zone Alarm and I have setup access etc OK. I know this has to be something as simple as a tick in the right box but I am now lost for ideas…..any suggestions welcomed.