We have successfully configured our site to use windows authentication för editors and admins (using the Multiplexing provider) but we can't seem to get it right for the Commerce Manager site.
Ideally, the sites should same the share auth cookie (Commerce Manager on same domain) so you don't have to login again to Commerce Manager. But not even this works for the regular authentication...
To save us some headaches trying to make this work - is there anybody out there who have successfully configured Commerce Manager for Windows authentication? Please share your wizdom!
Not sure about the version you're using but recently (months ago) I fixed a bug related to Windows authentication for Commerce Manager, which effectively prevent the login. http://world.episerver.com/Support/Bug-list-beta/bug/114954/
So for my knowledge I don't know any partner has successfully used Windows authentication for CM. This is also not officially supported by EPiServer Commerce, then you might need to contact our support service for further assistant.
EDIT: want to clarify a bit. I "heard" that some partners has bên using Windows authentication for CM, but I don't know details about them and their cases, so for me it does not count.