The error you are getting is because the machine is not associated with a domain.  It is generally best to go one route or another.  You are going to have to know whether you are running Windows Auth or not before the login form comes up.  You may have a registry value that determines if this is a Windows Auth machine or not.

I'm running into problems when I set SecurityBasics.AllowWindowsAuth = True in the AppMain.

In some cases I want to allow windows authentication, but in many cases I don't, such as sales reps laptops etc...

When I set AllowWindowsAuth = True and the application runs on a stand-alone machine, I get an error: "Current security context is not associated with an Active Directory domain or forest".

I guess the bottom line is I need to be able to run my application in both environments. Is there a good way to handle this situation? 

Thanks

Tim