Windows 10: Cannot open Windows "START" screen

Selecting the "Windows Button" on the keyboard or the Windows "Logo" on the Taskbar doesn't open the Start Screen anymore. Windows 10

:)

 

Black screen after 'Starting Windows' sequence

Sounds like the old... windows black screen of death.

Try this quoted from "VisiHow" article "Repair Windows 7 Black Screen of Death":

They, also, have some other options there, too.
Google search and you will find a lot of the "Windows Black Screen of Death with cursor" fixes.

 

Have Start screen open with “All Apps” list already opened?

Version 1607 Build 14393.105 does that, click Start and the full Apps list is scrollable.
Forgot to add this screenshot:

 

Start Screen not opening.

Hello,

When you're experiencing issues opening Start Menu, this article can help in resolving
the issue. Please follow all the suggested steps and report back to us if the issue would still persist. I also suggest that you run a scan using
Windows Defender Offline to be sure that your device is secured.
Go to Settings > Update & security > Windows Defender> Select Scan Offline. This would take around 15 minutes and restart your device.
To see the scan results:

• Select the Start button, then select Settings > Update & security > Windows Defender.
• On the History tab, select All detected items, then select View details. Any items detected by Windows Defender Offline
  will be listed as Offline in Detection source.

Update me if there are improvements.