Windows 10: HELP! windows boot manager error ???

I have Windows 11and one of my laptops Lenovo suddenly will not boot. I get this message: Under Setup Notice: Default Boot Device Missing or Boot Failed. HELP!!!!How can I fix this?Meredith

:)

 

Windows boot manager

There could be some system conflict triggered after the said changes. To help you with your concern, we suggest that you perform a clean boot. A
clean boot is performed to start Windows by using a minimal set of drivers and startup programs. This will help to determine what is causing the issue on the Windows boot manager. To do this, click on this
link and scroll down to the
How to determine what is causing the problem by performing a clean boot section then follow the steps listed..

Note: If the installation is successful and the issue has been resolved. Please go through the section “How to reset the computer to start as usual” to reset your computer to the normal startup.

Let us know how it goes after performing the suggested steps.

 

Windows 10 Boot Manager error 0xc000000f

Hi,

The error code you're getting might be due to corruption of some boot files which help the Windows operating system to boot or load on the computer. We suggest performing a Startup repair on your computer. It will help to repair the master boot record to
get things up and running again.Kindly check the steps below:

• To access the recovery environment, turn your computer on and off three times. While booting, make sure you turn off the computer when you see the Windows logo.
  
• Once you're in the recovery screen, click on Advanced options.
  
• Click on Troubleshoot, then Advanced options.
• Lastly, select Startup Repair.

Let us know if you have any other questions.

 

Multiple Boot Managers and/or active partitions error

I don't know what you did to fix previously but with the commands above should rebuild the the partition unless the partition itself is corrupted preventing you to run those commands.
Let's try another way:

1. Download the Macrium Rescue disk: MacRescue.iso - Google Drive
2. Using a USB stick to create a bootable USB with: Rufus - Create bootable USB drives the easy way
3. Boot up the PC with UEFI Mode and follow the screen shots to rebuild the EFI System partition.
   NOTE: The title must show: ..... Win PE 10 [UEFI] for step 3 to work since your Windows installed with GPT disk.

IMPORTANT: make sure you use the correct disk in step 2, in your case is disk 1