You can't find documentation because there are just too many variables for a one size fits all approach, the end information is the same, but getting to it varies by Operating System, and sometimes even Service packs within them.
With Windows 10 the printer needs to be very specific with the formatting, so on the PC go to the share Properties and make certain that the username on the webpage matches the PC how it is displayed in brackets, not the way you type it when you log in.
Also, Case sensitive for everything. Windows can fix upper and lower case but the printer can't and won't.
