When you remove the Linux drive, Grub also gets erased, or sometimes you even accidentally delete or format the boot partition, so you have to replace the Ubuntu/Linux boot loader with the Windows boot loader. Windows boot files will need to be recreated. You will need to create a Bootable Windows USB Drive to fix the boot files.

gurub-rescue

Follow the below steps to fix the error:

1.    -Create a USB device with an iso image.

Read this post : How to Create a Bootable Windows 11 USB Drive: A Step-by-Step Guide

2.    -Enter on BIOS/UEFI and change to boot from the USB device.

Changing BIOS settings varies depending on the model and make. You can search Google or YouTube to change the BIOS settings on your PC or laptop.

boot-priority-with-usb-drive


3.    -On installation screen click on "Repair your computer" on the left bottom

repair-your-computer


4.    -Click on "Troubleshoot" and then the Advanced Options page will appear.


troubleshoot windows


Troubleshoot-Windows-Advanced Options


5.    -Click on "Command Prompt".

Command-prompt


6.    -Select the correct drive where Windows is installed.

Default is the drive C:

Type C: [enter]

Type DIR  [enter]

The Windows directories such as Program files, Program Files (x86), Users and Windows will be displayed by this command. If these folders are not visible, try another letter, such as D:, E:, or F: (Depending on Hard Drive/Partitions you have installed)

cmd-directory-command

Now run the below commands to fix the partition after you've located it.


7.    -Run these commands one by one
 chkdsk C: /f /r  [enter]
 bootrec /fixmbr  [enter]
 bootrec /fixboot  [enter]
 bootrec /scanos  [enter]
 bootrec /rebuildbcd  [enter]
 sfc /scannow  [enter]

 8.    - Remove the USB media and Reboot your pc. You should be all set now.