If your LAN Clients are connecting to a computer on the internet on port 8090, then all they need is NAT. To test for it from the LAN Client, ping the following; the first is to test for DNS resolution, and the second is for gateway connectivity:
(Windows) Start menu --> Run --> cmd --> ping
www.wingate.com
(Windows) Start menu --> Run --> cmd --> ping 210.55.214.36
If they cannot ping, then the problem could be:
1. LAN Client has no default gateway set to WinGate
2. LAN Client has no DNS Server that can perform internet DNS resolution.
3. The Extended Networking Service in WinGate does not have NAT enabled.
4. The Extended Networking Service is not installed.