Hi, I'm Bernard, a fellow Windows user. I'm happy to help!
Have you noticed any changes before the issue starts? As per checking the error, we need to use Windows installation media on a USB to repair the issue. To do that, kindly follow the steps below:
Note: We need another PC and a USB drive (At least 8GB and make sure there are no files inside, as it will reformat the USB) Once you have that, kindly follow the steps:
Step 1: Create Windows 10 installation Media
Go to this link: https://www.microsoft.com/en-us/software-download/windows10
Scroll down and click "Download Tool Now" then run the Media Creation Tool (the downloaded file)
If you agree to the license terms, select Accept.
On What do you want to do? page, select Create installation media for another PC and then select Next.
Select the language, edition, and architecture (64-bit or 32-bit) for Windows 10. This table will help you decide which edition of Windows 10 you’ll choose:
On Select which media, you want to use click USB and save it to your USB drive.
Once done, do the repair kindly follow the steps below:
Insert the USB into the affected PC
Start the PC, and if you see “Press any key to boot from DVD,” do so. If you don’t see the message, you might need to change the boot order in your computer's BIOS settings so that it first starts from the DVD or USB.
When you see the Install Windows page, tap or click Repair your computer to start the Windows Recovery Environment.
In the Windows Recovery Environment, on the Choose an option screen, tap or click Troubleshoot.
Tap or click, advanced options, and then click on Startup repair.
For reference: https://windowsreport.com/windows-10-repair-usb/
Note: This is a non-Microsoft website. The page appears to be providing accurate, safe information. Watch out for ads on the site that may advertise products frequently classified as a PUP (Potentially Unwanted Products). Thoroughly research any product advertised on the site before you decide to download and install it.