Well seemings it is a small network, static IP the desktops and hoping the printers e.t.c are static as well. No point running DHCP Also, run netsh dump and ipconfig /flushdns <----too clear any network cache that could be causing an issue. The ping result sounds like the ARP table responding to your ping request. Also, are windows firewall enabled on the desktops ? If so, disable them, no need having them on as they can block ICMP requests.