Re: wireless network
danday wala I dont think its the key, If it would prompt him to enter the key
What router is it??
If its connecting to other unsecure networks but not connecting to your own then you might have Remote Managment enabled.
I think its called Remote Managment where you have to actually put in the Mac address of the laptops Network card
Its Remote sometthing, havent done it in a while so have forgotten the correct term for it.
Or you can jsut turn it off but then that leaves your network unsecured and just like you, your neighbours will be able to connect to your network and use all your Usage.
Bascially with this feature other computers can see the network but only those with the Mac address in its settings can connect.
No Adrasteia, it doesn't always try to negotiate the security keys from the client side by default (hence no prompt). It really depends on the client side implementation of the wireless protocol (an un-updated version of Windows XP, for instance, does not support it).
As for the MAC address, when the client tries to connect with the router, router already gets the MAC address, and it asks the owner if this MAC should be allowed (if the option is enabled indeed). So no need to manually enter the MAC address yourself.
Apart from this, there might be many other reasons. I'll try to list one more here:
Now we know that he is using a D-Link wireless router. I take that it supports 802.11g protocol, the interesting question will be if his laptop's W-LAN card supports it as well?
@Saieen: could you connect with your router with an Ethernet card (IP is ususally 192.168.2.1 or something similar) and check the Error Logs there? It could give you a better diagnostics of the problem.