It says boot device not found please install an operating system on your hard disk

[RitaB32]

Please install an operating system on your hard disk 

[BeemerBiker]

Either the disk is defective or the OS cannot be found because of a startup problem.

Tap the ESC key after powering on. Tap it once a second after you see the LEDs on the keyboard flash. When you see the startup menu, press F2 to run diagnostics.  Make sure that the memory and disk drive diagnostics pass.

If a component fails during the UEFI test then Click here to check warranty

If disk fails you need to replace the drive.  let me know.

If diagnostics pass then the file system is corrupted and you need to repair Windows startup

First read this article about safe mode. Skip down to 'Enter safe mode from outside windows. If F11 does not get you into system recovery then try turning the power on and off three or more times in a row.

Try that Startup Repair shown just above.

If that does not work then go for a Restore Point.

This video describes how to use a restore point. Ignore that it shows windows working. Clicking on System Restore will bring up the list of restore points similar to what is in the below video.
https://www.youtube.com/watch?v=sixGAIiPTlE

If there are no restore points or the restore point is so far back that you'll lose a lot of programs then you need to bring up the device manager and see if you can fix the problem.

Find the device that has the error icon and try to fix it.