Shared wireless key

Hi,

I have four computers connecting to a wireless dlink router in an
office. The computers are all on static ip addresses. Three of these
computers work fine but one of them keeps dropping the shared key and
losing the connection. Is there anything I can do to make the settings
stay there? I've tried restarting the wireless config service but that
doesn't help. The wireless laptops are using windows to manage the
connection. Anything else I can check?

Thanks,

Andrew