Wireless adapter not connecting

I just got a new computer.
Its HP Vista home premium
My other computer is wired (router)
My laptop connects just fine to the router.
The first time we setup the computer it connected to the router but now
it wont.
It will either find it and say the capability of this network adapter
does not meet the requirements of this network.
Now it connects and has a horrible signal and is very slow
Thanks!


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ramez