As a temporary fix for your four computer network... Ring up your ISP and ask them to give you the ip addresses of two of their DNS server.
Place them in (Windows) Start menu --> Programs --> WinGate --> GateKeeper --> DHCP Service (As shown in images below).
3. Add the router (gateway) --> Double Click the router label you added, and place in 192.168.33.50
4. Add the DNS Server --> Double Click the DNS Server label you added, and place in the two DNS IP Addresses which you got from your ISP.
Now...
Go to the client machines that have already got an IP address via DHCP, and renew the addresses to get the new DNS server.
Win NT / 2000 / XP
(Windows) Start Menu --> Run --> cmd --> ipconfig /renew --> Restart the pc
Win 9x
(Windows) Start Menu --> Run --> winipcfg --> Select your network card from the drop down list, and click the renew button. Restart the pc
Now, that your network should be operational... Can you please send us a configuration report to jamesc at qbik dot com ... And we will try and find what the problem is.
GateKeeper --> Options menu --> Advanced --> Save Report (as shown in image below).