Hi Steve,
The best option for you would probably be to use the WGIC(WinGate Internet Client) with NTLM authentication. This would require upgrading to a Professional license though. Why don't you activate a trial license to make sure it works for you before you purchase the upgrade. If you've trialled version 6 on this machine before then we'd be happy to extend your trial license for you, just send in a trial email activation request and ask for an extension in the email.
Using the WGIC and NTLM you would specify that authentication is required in the WinSock Redirector Service. The clients would each run the WGIC on their machines. The WGIC sends through the NT user information to the WinGate server which verifies the authetication. As long as the username and password is correct the users won't see an authentication prompt.
You can then create policies in the proxies, requiring all users to be authenticated (but don't specify the type of authentication, because this can confuse the issue) and only users who are authenticated with the WGIC will have access.
Using NTLM requires you to use the Operating System database in WinGate, but this is quite straightforward. Installing the WGIC on the client machines can also be done very easily, just add the WGIC.msi file to the login path, for more information see our knowledge base article here,
http://support.qbik.com/index.php?_a=kn ... ils&_i=110
Regards,
Matt