Windows 10: Computer randomly restarts and says operating system not found.

So I am trying to run a minecraft server on my computer and it works fine but is randomly shuts off and says "operating system not found" I've tried multiple things and nothing has worked. Here's a picture of what it says:

:)

 

random restarts

Hi Lili,

Hardware failure or system instability can cause the computer to
randomly restarts. As our initial troubleshooting step, we suggest you to run the Power troubleshooter on your computer and check if it fixes the issue. Here are the steps:

• Press Windows key.
• Type Troubleshoot.
• Under Find and fix other problems look for
  Power.
• Then Run the troubleshooter.

Update us with the outcome and if you need further assistance.

 

computer randomly restarts multiple times

Hi,

Welcome to Microsoft Community and thank you for posting your query.

Let me help you to fix the issue.

To understand the issue better, please provide us more information.

• 
  What is the make and model of the computer?
  
• 
  When does the system exactly restart? Please elaborate.
  
• 
  How did you upgraded to Windows 10 through Windows update or Windows 10 ISO?
  

Let’s try simple steps and check if this helps. Follow the below steps.

Method 1.

I suggest you to check the settings, if the automatic restart is set on the system.

• 
  Open file explorer and click on Computer on the top pane.
  
• 
  Click on System properties and click on
  Advanced system settings.
  
• 
  Now click on Advanced tab and click on
  Settings button on Startup and Recovery option.
  
• 
  Uncheck on Automatically restart.
  

If the issue still persist try the below methods.

Method 2.

I suggest you to boot the system in Clean boot state and check if the issue still persist.
Clean boot process will help you determine which third party program/app that is causing this issue. It could be some other application or programs, which runs on the computer at the background, leading to this issue. Please visit the below link
on how to perform Clean boot.

https://support.microsoft.com/en-us/kb/929135

Disclaimer: Please go through the section: How to reset the computer to start as usual after troubleshooting with clean boot of the Kb article to boot the computer in normal startup after fixing the issue.

Hope this helps. If you need further assistance with Windows, let us know and will be glad to help.

 

After updates Windows 10 says "Missing operating system"

I have the same issue, and I followed your suggestion steps. After that, I can see C: drive, and Windows folder is there.

Then I rebooted the computer. But I still have the missing the operation system issue. Any suggestions?

Thanks.