Cant connect to wireless network link 5100 AGN

I bought a gateway UC serie, with windows vista 32 bits, my wifi card is a Intel link 5100 AGN N draft.
Since I got the laptop I cant connect to my wireless network, well, I can connect a meter from the router, but If a move a little bit I cant... it said windows didnt recieve any response. There are 3 more laptop that can connect easily a lots meters away.
The guys from the company of internet said the router is ok...... because other 3 computer are connecte fine. The support said the card is ok because it can connect.
If Im a meter away from the router is ok, the speed is nice to.
The laptop detect the network but cant connect, I have tried at other places, and its the same.

The router is b/g............ and I have enable a/b/g and n

I have desinstall and reinstall, update driver... nothing

I would appreciete your help
Rafa