I have WinGate installed in our DMZ.
No traffic is allowed to directly flow from the LAN to the Internet.
So all WWW traffic has to flow via WinGate, a hardware firewall redirects all port 80 traffic from the LAN to WinGate.
So far all good.
The problem is that WinGate never prompts for a username / password, and assumes everyone is "Guest".
I've tried the instructions "Authenticating all Users through WinGate"