Windows 10: time lap of more then 20 minutes before start-screen windows appears..

When i press the start button of my compu , it takes between 20 and 30 minutes before the start screen from windows is appearing, and until that moment , i only see the black screen...
What could be the reason for this great time lap between pressing start button compu and appearing the startscreen from windows?

:)

 

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.

 

Clock always 20 minutes fast if set on automatic

There's at least 3 places on this list that have 30 minute offsets but that doesn't explain 20 minutes:
The World Clock Worldwide

 

Wifi connection cutting off every 20 minutes

My internet is turning itself off about every 20 minutes, and I have to go to the network and sharing center and run troubleshoot wifi connection 3 a several times before it goes back to normal.

What I've checked:

• The internet works without fail on my phone. The problem is surely on this device.
  
• The wifi connection 3 thing on network and sharing center is the thing that always goes offline (has a red cross next to it)
  
• My intelligence... I'm pretty bad at computing so please explain this in steps.
  

I'd really appreciate it if someone could tell me how to stop this inconvenience from occurring every 10-20 minutes, its really frustrating. I need to answer questions and get more reputation on writers SE .

Thanks. By the way, I ran a scan. Its not a virus or malware, whatever else it could be.