Wireless Woes

[OLD JUD]

I've just had a Gigaset SE572 WLAN dsl router delivered today from Orange, Connected to my desktop PC (Wired) running Windows 7 without a problem, then i tried to get a wireless connection to my wifes HP Compaq NC 6400 (Win XP service pack 3) laptop so she can use the internet, laptop is picking up the router and stating that the signal is excellent, the the installation CD is saying it can't pick up the router?

The same happened when i rebooted my desktop into XP, any ideas guys?
No matter what i do i cannot get internet on the laptop.

I know nothing about networking so i really need a 'Dummies guide' please!

 

[OLD JUD]

Anyone?

 

[tolien]

You don't need a CD, for starters. Does it actually connect to the router and get an IP? Can it see the router's web interface, ping it, or anything else?