I have been pulling my hair out trying to get ESET Smart Security to work consistently with the computers on my LAN. Two desktops and one laptop are wireless; my main computer is hard wired to the SMC Barricade SWC20804WBRP-G router. At varying times, I get frequent error messages on any or all of the computers that the workgroup is not available or a particular computer is not available; this happens all the time with the one that is cable connected to the router. When I disable the firewall component of ESET the network runs flawlessly. This is telling me that it is not likely a Windows problem I have unticked under Intrusion Detection ARP and DNS poisoning attacks as per ESET's recommendations. This has not solved the problem. It does appear that I am missing some settings somewhere; the firewall is set to allow sharing. I have also tried adding the two way UDP rule on port 137-139 to no avail. That has helped for a while sometimes but not consistently. If someone has some idea as to what I might be missing, please let me know. I do love this program a lot but it is of no use to me if I can't see my computers on my network. Thanks a lot for your help.