Remove USB drives and discs, enter the BIOS/UEFI and check that your SSD/HDD is detected and first in the boot order, and that boot mode matches your disk (UEFI for GPT). If the drive is listed, repair boot files from Windows Recovery. If it isn't, the drive or its connection has failed.

Why this happens

At power-on, the firmware looks through the boot order for a drive containing a boot loader. HP laptops show “Boot Device Not Found (3F0)”, Dell shows “No bootable devices found”, and others say “Reboot and select proper boot device”. They all mean the same thing.

The key question is whether the BIOS can see the drive. If it can, the problem is configuration or boot files and is generally fixable. If it can’t, the drive has failed or come loose.

What you'll see

  • “Boot Device Not Found. Please install an operating system on your hard disk (3F0)”.
  • “No bootable device. Insert boot disk and press any key”.
  • “Reboot and select proper boot device”.

What causes it

  • USB drive or disc first in boot order.
  • Boot mode changed (UEFI vs Legacy/CSM) after a BIOS reset or update.
  • Corrupted boot partition or BCD.
  • Failed, disconnected or loose SSD/HDD.

How to fix it

  1. Remove external mediaUnplug USB drives, SD cards and discs and restart.
  2. Check the BIOS sees the driveEnter setup (F2, F10, Del or Esc at power-on). Look for your SSD/HDD under storage or boot information.
  3. Fix boot order and modePut Windows Boot Manager (or the drive) first. If the disk is GPT, use UEFI; if MBR, use Legacy/CSM. Load defaults if unsure, then re-check.
  4. Run a hard reset (laptops)Unplug power, hold the power button for 15 seconds, reconnect and start. Some HP models clear 3F0 this way.
  5. Repair boot filesWhen no boot device is found Windows never starts loading, so its built-in recovery can't open. Make a Windows installation USB on another PC with Microsoft's Media Creation Tool, boot from it, choose Repair your computer → Troubleshoot → Startup Repair, or open Command Prompt there and run the commands below.
  6. Test the driveUse the PC maker's built-in diagnostics (F2/F12 menus) to test the drive. Reseat it if you can. Replace it if diagnostics fail, then restore from backup.

Command

bootrec /fixmbr
bootrec /fixboot
bootrec /scanos
bootrec /rebuildbcd

Run from Windows Recovery → Troubleshoot → Advanced options → Command Prompt. On UEFI PCs, if /fixboot says 'Access is denied', rebuild the boot files with bcdboot C:\Windows (check the Windows drive letter with dir first).

How to tell it worked: The PC starts straight into Windows with no boot device message.

Stop it happening again

Avoid changing BIOS boot mode, keep backups, and watch for drive health warnings.