Summary
Solve the black screen problem during system startup by modifying the kernel DMA protection strategy in windows.
Description
Case 1: If only graphics card dock is connected and the display is connected to any monitor , you can see splash screen, BIOS frame (if entered) and windows loading frame. After windows is loaded, monitor will not output the windows login frame（black screen）. after blindly entering the password, then the screen will be displayed.
Case 2: Both using dock and NUC HDMI port with each monitor. you can see splash screen, Windows loading frame on dock side. Then Windows login frame jump to HDMI side. After login, frame back to the dock one.
Resolution
- Press Windows key + r
- Type gpedit.msc
- Navigate to Computer configuration - Administrative templates - System - kernel DMA protection
- Modify the Enumeration policy of external devices incompatible with kernel DMA protection to Enabled, and select allow all in the enumeration policy
- Restart the system