Sorry in advance if you said this already, but can't find any reference to firewall except in Tony's post. Are all firewalls relevant ports open? As a quick test, you could disable firewalls and see what happens. I've put many Windows 7 and Vista in a fairly large LAN/WAN einvironments, and the only problems I had in seeing other pcs was caused by firewall misconfigured. Windows Vista and 7 adds some issues at first setup because when you choose among "home", "public", "office" network setups, what happens is that ports in teh firewall are configured so to allow or disallow specific traffic type. In theory, Office or Home should give you no problem.