6TOP Adapter

Hi
We have connected 1Notebook XP and one PC XP and my Notebook Vista basic
with the rooter WAG200G. The other two with cable, my wireless. Internet
connection works properly, but I cannot see the other two neither they see
me. All helps I could find didn´t solve my problem. I found in the device
manager, that the Adapter is not working right. But searching for a solution
in the internet the system cannot find a solution. Maybe this is the reason
why I cannot see the others. Who can help me?
Thanks Beate