I also have this problem, and would like to have an official solution from Dell. This is an annoying issue with this otherwise fine laptop.
This solution doesn't work for me using Windows 10 Pro anniversary edition. Both .exe files fail to install the keyboard backlight feature, although they install the user guide! Any other ideas?
I agree with the others regarding the need for an OFFICIAL solution from Dell DESIGNED FOR XPS 9550 systems. We should not have to rely on installing outdated software for basic functionality. These are expensive systems. Can anyone from Dell please comment on whether this is in the works??