I have a windows 10 64 bit machine with all available updates. I have an evga nvidia 1080 gtx card with latest nvidia drivers. I have an asrock z170 itx mb with latest bios (7.1). I have PCI selected as my primary graphics card. I have disabled the onboard graphics in the BIOs.
When the hdmi port from my vid card is connected to my monitor, there is signal during the BIOS boot process, then I see the windows icon and about 2 seconds of the loading spinny wheel, then the screen goes black and no signal.
 
If I boot into the BIOS, the hdmi output works fine so it's not a monitor, mb or graphics card issue.  I have tested the cable and monitor using my wife's laptop and they work fine over hdmi.  Monitor has a native 1920x1080 resolution.  It's something in Windows 10 that decides it doesn't like HDMI at some point during the boot process. I have tried uninstalling and re-installing drivers. No luck.  I have tried resetting the bios using the button on my motherboard.  No luck.
 
Everything I have read about this problem in online forums I have already tried without progress. Does anyone have any other ideas as to what I can try?

Inside the motherboard bios make sure the pci-e lane is set on Gen3 mode and not Auto.

The only time that happens to me is when I have a second monitor hooked up and windows is actually on the monitor that is turned off.
I would try a dvi cable , just to install the latest drivers there have been many bugs lately

xrav22.  I have only one monitor.  DVI does work however I need hdmi to work since I have an HDMI kvm that my wife and I use to share a monitor/keyboard.
 
Sajin, I will try your suggestion shortly.  Thanks.

Tried setting to Gen 3.  No luck :-(

You are connecting directly to the pc right now without going through the kvm?

Might just be the way the devices are communicating via the switch. If you go direct, it works?

May even try wiping your Nvidia drivers and reinstall.

3etatester
May even try wiping your Nvidia drivers and reinstall.

+1
 
Use ddu to remove your nvidia drivers then perform a clean install. Details on how to do this can be found here under step #2. If doing step #2 doesn't help then your gpu may have a faulty output.

I know you said you tested the cable on your wife's computer, but do you by chance have a different HDMI cable to try on your system.  Just a thought.  I've seen certain cables cause issues sometimes.

Ok, looks like it's something going on with the KVM and windows 10.  I tried all the components separately with my wifes laptop then connected by PC to the KVM and it didn't work so I thought it was related to windows (the KVM is brand new).  I'm going to some digging to see if there is an issue with this KVM and win.10