How to Fix No Bootable Device Errors on Windows 11

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My Technician
Windows 11BootHardwareFix

The Problem

At power-on you get No bootable device, Operating System not found, Reboot and select proper boot device, or No boot device available. The PC can't find a drive to boot from. Causes range from a wrong BIOS boot order to a corrupt bootloader—or a disconnected or failing drive.

If Windows starts but loops, that's different: Automatic Repair loop or stuck on the loading screen.

Quick Fixes (Try These First)

Remove USB Drives and Reboot

A plugged-in USB stick or external drive can hijack the boot order. Unplug everything except keyboard and mouse, then restart.

Reseat the Drive

If you recently opened the PC, power off, unplug, and reseat the SATA cable or M.2 SSD. A loose connection produces this error exactly.

The Fix: Step-by-Step

Step 1: Check the BIOS Boot Order

  1. Power on and tap Del, F2, F10, or Esc to enter BIOS/UEFI.
  2. Open the Boot menu.
  3. Confirm your Windows SSD/HDD is listed and set as the first boot device (look for "Windows Boot Manager").
  4. Save and exit.

Step 2: Confirm the Drive Is Detected

  1. Still in BIOS, open the main or storage information page.
  2. If your drive is not listed, the issue is physical—reseat cables/M.2, try another SATA port, and test the drive in another PC if possible.
  3. If it appears, continue to repair the bootloader.

Step 3: Match the Boot Mode (UEFI vs Legacy)

For a drive cloned from an older PC or a non-UEFI install:

  1. In BIOS, check Boot Mode—a UEFI Windows 11 install needs UEFI (not Legacy/CSM).
  2. Make sure Secure Boot matches how Windows was installed. A mismatch here causes "Operating System not found."

Step 4: Repair the Bootloader from Recovery

Boot from a Windows 11 installation USB → Repair your computer → Troubleshoot → Command Prompt:

bootrec /fixmbr
bootrec /fixboot
bootrec /rebuildbcd

If fixboot says Access denied, run bcdboot C:\Windows.

Step 5: Run Startup Repair

From the same recovery menu, run Startup Repair and let it finish.

Still No Boot Device?

  • If BIOS never sees the drive, assume a failing or disconnected disk—check drive health on another machine.
  • If the PC shows no display at all, it's not really a boot error—see PC won't turn on.

Drive detected but unbootable? Recover important files first with Data Recovery Pro before reinstalling Windows.