Just upgraded from Win 7 to Win 10. My 2nd monitor is not working

My computer is a recently purchased Dell with the Intel Graphics HD 530 display adapter. The outputs are one HDMI port (Monitor 1) and one display D-port (Monitor 2). I am connected to a pair of identical Samsung monitors. The D-port is routed through a passive display adapter for connection to the HDMI cord serving the second monitor. All my trouble is associated with Monitor 2.

During start up both monitors are used. The machine moves from the D-port monitor back to the HDMI port monitor during the startup process. At the end of the process only the HDMI monitor will display.

I tried swapping the cords around between the two monitors (switching up which was on D-port and which wasn't). Monitor 1 (HDMI-primary) works when connected to either the D-port cord set or the HDMI cord set. Monitor 2 (D-port primary) does not work on either cord set EXCEPT at machine start up when both monitors get used.

Prior to upgrading from Windows 7, everything worked. After the upgrade only the Monitor 1 works. I've tried removing and re-installing drivers. That didn't work.

Thoughts and suggestions?

Press the Windows Logo key and the P key, then select Extend. What happens when you do that?

I had a similar problem setting up My PC with a Radeon R380. The DVI-D monitor OK, the HDMI connected monitor no joy. Part of my problem was getting the drivers to load correctly but I had to go into the display settings in Windows 10 to get things fixed. There is a button in these setting that scans for other monitors. Once I had the drivers installed correctly this scan function did the job.