Windows Installed But No Boot

My PC suddenly stopped booting even though I didn't install or change anything. The error was ending with "D:\windows\system32\logfiles\Srt\SrtTrail.txt". When I turned on the computer, it was just giving the blue screen with "0xc000021a" error code, getting restared and trying to fix it but then the final error: "Automatic Repair Couldn't repair your PC".

I thought that this a good chance to learn how to fix hard errors like these and began to research for the errors. I found this link and tried the commands with the troubleshoot option:

bootrec.exe /rebuildbcd bootrec.exe /fixmbr bootrec.exe /fixboot

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But bootrex.exe /fixboot command gave the error "Access denied" and it didn't work. So I tried another recommandation which made things worse. I tried the bootsect.exe /nt60 all /force command. Now, when I turn on the computer, there is the error "No bootable device. Please restart your computer". Now, I have Windows Installation Media USB. I can go to Command Prompt and see that my files is kept in D:\ with all windows folders. However, I have no idea how to make my PC boot.

Now, I can probably just install the Windows without keeping my files although there are important thing that I don't want to lose so I'm trying to execute the Windows somehow and reach my files. Can you help me about that?

Thank you for your interest.

You can reinstall Windows, trying to keep all your files and applications. That said, to be safe, make a disk image to another HDD, or large enough USB drive. Since you can't boot your PC, you need rescue media such as a bootable USB flash drive or DVD, made on a another machine.

A third-party imaging tool such as Macrium Reflect Free or alternatives can make rescue media using the WinPE OS.

• Boot from the rescue drive or DVD.
• Make a disk image, or at least use the WinPE file explorer to copy data to an external drive.
• Some of these tools can fix some boot problems without reinstalling Windows.
• If boot repair fails, then try reinstalling Windows 10 downloaded from Microsoft, using the repair option, keeping files.

N.B. Since you state, "My PC suddenly stopped booting even though I didn't install or change anything," find the cause of the issue. Is your HDD failing? Did malware cause the issue?