I have a user in one domain (abc.com) trying to access the internet via an ISA proxy which exists in another domain (xyz.com).
Usually I just uncheck enable integrated windows authentication and the proxy prompts for credentials; I can then use credentials for xyz.com.
This works fine with our Xp/Vista IE 7 machines; but this is a Windows 7/IE8 machine.
However the authentication challenge is not presenting and the users currently logged in credentials (eg firstname.lastname@example.org) are being passed to the ISA server and failing (this can be seen in the ISA logs)
If the user logs onto a local account (ie not the domain) the authentication challenge appears and all works ok.
I do not want to monkey with the ISA servers config.
Any help with resolving this problem appreciated.