Windows 10 error - Unsupported video configuration detected. Action is required. This computer has an add-in graphics card, but the monitor cable is plugged into the integrated video connector...
You connected the monitor to the onboard video port, bypassing a third-party video card (e.g. NVidia, etc.), and began the Windows 10 install. You did this in order to see the BIOS setup screens to change the boot order. See Keyliner article: Black or Hung BIOS Setup Screen XPS 8700
1. Power off the computer, as instructed on the error
2. Chose one of these options or the other:
a. Physically remove the third-party video card and keep the Display Port or Onboard Video
b. Or disconnect the onboard video cable and only use the third-party video card
Middle of a Windows 10 Install?
If you were in the middle of a Windows 10 installation, boot the computer. At the "Press any key to boot from CD" -- do nothing... wait. Allow the computer to boot from the hard drive and the Windows install will continue from before the error.
If you allow Windows 10 to finish the install using the onboard video, wait for a finished desktop to appear. Then, power-down the computer and re-install the third-party video. Detatch the onboard video cable. Reboot. Then install the (NVidia or third-party video drivers). If found this to be difficult and frustrating process. Unfortunately, I did not record the exact steps.