Shoutbox

What you need to do is make sure that each computer has the same "Network Key". If they don't have that "key", they generally come up with the limited / no connectivity.

The best way to check is to always use the software given for you network adapter. Never let Windows XP do it unless the wireless adapter is inbuilt to your computer/notebook.

If any computers use a network cable to connect to the router, then there shoudn't be any problems.