There are a handful of reasons why a unit would not show up on your iHelp window.
One: GC-100 beacons broadcast every 60 seconds, and can therefore take up to one minute for iHelp to register the unit. If you would like to force a beacon broadcast, execute iHelp on the networked PC and then power up the GC-100. The unit will broadcast a beacon upon network connection negotiation.
Two: iHelp requires a network resource, in that it joins the multicast group in order to receive unit beacon messages. If your firewall is blocking iHelp from joining the multicast group, it would be unable to find the unit.
Three: Your PC is connected to multiple network interfaces simultaneously, causing iHelp to choose the incorrect one and join the incorrect multicast group. Make sure that you are connected to the same network as the iTach, and that you are connected to only one network in order to confirm that this is not the problem.
Four: You have a firewall, addressing issue or network setting which is blocking traffic at some juncture. As this is a relatively open statement, there are a few places that need to be checked. Router settings (UDP traffic, routing, subnetting and addressing) should be checked, as well as any connected network switch (in line between the iTach and the networked PC), and dedicated firewall programs.
If you continue to have this problem, using a different PC on the network to attempt to discover the unit will give you helpful information. Either the unit is not discoverable from both PCs, meaning that this is probably a network issue, or the unit is discovered by the second PC, meaning that the issue has to do with some sort of setting on the first PC.
If these suggestions did not help, please send an email to firstname.lastname@example.org and we will make sure to get you up and running as soon as possible.