How to Fix “BootDevice Not Found” Hard Disk (3F0) Error in Windows

When starting the computer, you may see a black-screen error similar to this:

This error means the computer cannot find a bootable operating system on the selected disk. It does not always mean Windows has been deleted. In many cases, Windows is still on the hard disk or SSD, but the computer cannot start it because of a wrong boot order, incorrect UEFI/Legacy boot mode, damaged boot files, corrupted BCD configuration, storage controller setting changes, or a disk detection problem.

Step 1: Run System Diagnostics First

If the error screen offers F2 System Diagnostics, press F2 and run the hard drive or storage test first. This is especially important when the message includes Hard Disk - (3F0).

Step 2: Check BIOS/UEFI Settings

Restart the computer and enter the BIOS/UEFI setup screen. Common keys include F2, Del, Esc, F10, and F12. Press the key immediately after powering on the computer.

Common Causes of BootDevice Not Found / Hard Disk (3F0)

After the disk is detected and appears healthy, this error is often caused by one of the following boot problems:

• Wrong boot order or wrong boot device selected
• BIOS/UEFI boot mode changed from UEFI to Legacy/CSM, or from Legacy/CSM to UEFI
• Damaged MBR on a Legacy/MBR system
• Damaged boot sector or boot sector parameters
• Incorrect active/system partition on a Legacy/MBR system
• Corrupted or missing BCD file
• Missing EFI boot files on a UEFI/GPT system
• File system errors on the boot partition
• Boot configuration damaged after disk clone, restore, repartitioning, Windows update, or power failure
• Storage controller mode changed, such as AHCI, RAID, Intel RST, or Intel VMD

Method 1: Repair BootDevice Not Found with Lazesoft One Click Fix

If you do not want to manually identify partitions and type commands, use Lazesoft Recovery Suite Home Edition or Lazesoft Windows Recovery Home Edition. The One Click Fix feature can automatically check and repair common Windows boot problems. You can also watch the video guide above to see the process before following the steps below.

Step 1: Boot from a Lazesoft Recovery USB Disk

Boot the problem computer from a Lazesoft recovery USB disk. After Lazesoft Recovery Suite starts, select Windows Recovery from the main screen.

Step 2: Choose One Click Fix Crash Solution

In Lazesoft Windows Recovery, choose One Click Fix Crash Solution. This option is designed for common Windows boot and crash problems.

Then click the One Click Fix button.

Step 3: Select the Windows Installation

If Lazesoft finds more than one Windows installation, select the correct Windows installation you want to repair. Check the Windows version, boot volume, disk size, and system volume information carefully before continuing.

Step 4: Run One Click Fix

Lazesoft One Click Fix will check and repair common Windows boot problems automatically. It may check and fix the MBR, boot indicator, boot sector parameters, boot sector boot code, BCD file, file system on the boot partition, missing critical Windows system files, and Windows boot-related registry files.

Step 5: Reboot and Test

After the repair is completed, click Finish, remove the Lazesoft USB disk, and restart the computer. If the repair is successful, Windows should start normally again.

Method 2: Repair the Error Using Windows Commands

This method uses Windows Recovery Environment or a Windows installation USB disk. It is suitable for advanced users who are comfortable identifying partitions and running command-line tools.

Step 1: Boot into Command Prompt

Boot the computer from a Windows installation USB disk. On the Windows Setup screen, click:

Repair your computer → Troubleshoot → Advanced options → Command Prompt

Do not click Install now.

Step 2: Find the Windows Partition

Drive letters in Windows Recovery Environment may be different from normal Windows. Run:

diskpart
list volume

Look for the Windows partition. It is usually a large NTFS partition. Exit DiskPart:

exit

Then test possible drive letters:

dir C:\Windows
dir D:\Windows
dir E:\Windows

Use the drive letter that contains the Windows folder. In the examples below, we assume the Windows partition is C:. If your Windows partition is D:, replace C:\Windows with D:\Windows.

Repair Method A: For UEFI/GPT Systems

UEFI / GPT

Use this method if Windows was installed in UEFI mode and the disk uses GPT. Most modern Windows 10 and Windows 11 computers use UEFI/GPT.

Find the small FAT32 EFI System Partition, usually around 100 MB to 300 MB:

diskpart
list volume

Assign the EFI System Partition a drive letter:

select volume X
assign letter=S:
exit

Replace X with the correct EFI partition volume number. Then rebuild the EFI boot files:

bcdboot C:\Windows /s S: /f UEFI

If the command succeeds, you should see:

Boot files successfully created.

Restart the computer:

wpeutil reboot

Repair Method B: For Legacy BIOS / MBR Systems

Legacy / MBR

Use this method if Windows was installed in Legacy/CSM mode and the disk uses MBR.

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

If bootrec /fixboot shows Access is denied, you can continue by rebuilding the boot files with bcdboot.

If there is a System Reserved partition

diskpart
list disk
select disk 0
list partition

Find the small System Reserved partition. It is usually NTFS and around 100 MB to 600 MB. Select it and mark it active:

select partition X
active
assign letter=S:
exit

Replace X with the correct System Reserved partition number. Then rebuild boot files:

bcdboot C:\Windows /s S: /f BIOS

wpeutil reboot

If there is no System Reserved partition

If Windows is installed directly on the active system partition, mark the Windows partition active and rebuild boot files:

diskpart
list disk
select disk 0
list partition
select partition X
active
exit

Replace X with the Windows partition number. Then run:

bcdboot C:\Windows /s C: /f BIOS

wpeutil reboot

Optional: Check the File System

If the boot partition has file system errors, run:

chkdsk C: /f

If your Windows partition uses a different drive letter in Windows Recovery Environment, replace C: with the correct letter.

chkdsk D: /f

Special Case: BootDevice Not Found After Clone or SSD Upgrade

If the error appears after cloning Windows to a new HDD, SSD, or NVMe drive, check these items before assuming the clone failed:

1. Make sure the cloned disk is selected as the first boot disk.
2. For a GPT target disk, boot the computer in UEFI mode and choose Windows Boot Manager for that disk.
3. For an MBR target disk, boot the computer in Legacy/CSM mode and make sure the correct system partition is active.
4. If the old and new disks are both connected, temporarily disconnect the old disk and test again.
5. If the clone was made to NVMe, confirm the computer supports booting from NVMe and that the storage controller setting is correct.
6. If Windows boot files were not created on the new disk, rebuild them with Lazesoft One Click Fix or the bcdboot command.

For more clone-related boot problems, see Fix 0x7B After Clone and Fix Windows Black Screen After Clone.

Reboot and Test Windows

After repairing the boot files, remove the recovery USB disk and restart the computer.

What If BootDevice Not Found Still Appears?

1. Run system diagnostics again and check whether the disk passes.
2. Confirm the Windows disk is still listed in BIOS/UEFI.
3. Check whether the correct disk or Windows Boot Manager entry is first in the boot order.
4. Confirm the correct boot mode: UEFI for GPT or Legacy/CSM for MBR.
5. Disconnect extra USB drives, external disks, and memory cards.
6. If the computer uses RAID, Intel RST, Intel VMD, or a special storage controller, make sure the correct storage driver is available in the recovery environment.
7. If the disk shows warning signs, clicking sounds, slow detection, or diagnostics failure, back up or recover important data before continuing.
8. If Windows was cloned or restored to a new disk, check whether the target disk uses the expected partition style and contains the required EFI/System Reserved boot partition.

Which Method Should You Use?

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