No Operating System Found After Cloning – Solved Now!

User case: Cloned OS won’t boot ("OS not found")

If you encounter operating system not found after clone, there are several possible causes:

• Connection or Hardware Issues
• Incorrect Boot Order in BIOS/UEFI
• Missing or Inactive System Partition
• Boot Files Not Copied or Damaged

How to fix no operating system found after cloning

In this part, you’ll get 5 effective solutions to the error no boot device found after cloning. You may try basic solutions first before you go to advanced ones.

👉 Basic troubleshooting:
Fix 1: Make Sure the Cloned Drive Is Recognized
Fix 2: Set the Correct Boot Drive
👉 Advanced troubleshooting:
Fix 3: Mark System Partition as Active (For MBR Disks)
Fix 4: Repair Boot Files (For Both MBR & GPT)
Fix 5: Use Automatic Startup Repair

Fix 1: Make Sure the Cloned Drive Is Recognized

The first thing you should do is to ensure your computer actually detects the cloned drive. If the BIOS or UEFI doesn’t recognize the new disk, Windows can’t load from it no matter how perfect the clone is.

1. Restart your computer. As soon as the manufacturer logo appears, press the setup key (usually Del, F2, F10, or Esc) to enter BIOS/UEFI Setup.

2. Once inside the BIOS/UEFI, look for a section named Boot, Storage, or Information.

3. In the drive list, you should see your cloned SSD or HDD listed. If it doesn’t show up, check your connections or hardware setup.

• For SATA drives: Make sure the data and power cables are firmly connected. Try using a different SATA port if possible.
• For NVMe or M.2 drives: Ensure the drive is properly seated in the slot. Some laptops require removing a screw and re-securing the module.
• For external cloning setups (via USB dock): Move the cloned drive inside the system and connect it directly to the motherboard for reliable detection.

Fix 2: Set the Correct Boot Drive

Even if your cloned drive is recognized by the BIOS, your computer might still try to boot from the wrong disk. Setting the correct boot drive ensures the system loads Windows from your cloned SSD or HDD.

1. Enter BIOS/UEFI Setup as mentioned in Fix 1.

2. Once inside, look for a tab or section labeled Boot, Boot Order, or Boot Priority.

3. Highlight your newly cloned drive (usually listed with its model name). Then move it to the top of the list using the indicated keys (often + and - or drag-and-drop on UEFI systems).

4. (Optional) If you cloned disks between different partition styles (e.g., clone MBR to GPT), you should match the correct boot mode.

• GPT disk → UEFI mode
• MBR disk → Legacy (CSM) mode

Note: If you don’t know the partition style of your cloned disk, connect it to another PC → open Disk Management → right-click the drive → Properties → go to the Volumes tab to check out.

5. Press F10 (or follow the on-screen prompt) to save changes and reboot. Your PC should now boot from the cloned disk.

Fix 3: Mark System Partition as Active (For MBR Disks)

If your cloned disk uses the MBR partition style, Windows requires one partition — the System Reserved or C: drive — to be marked as active. If the system partition isn’t active after cloning, your computer will show the “No operating system found” error. Follow the steps below to fix it:

1. Open Command Prompt. You can access Command Prompt in two ways:

• Boot from the old Windows drive → search for cmd, right-click Command Prompt, and choose Run as administrator.
• Boot from a Windows installation USB, click Repair your computer → Troubleshoot → Advanced Options → Command Prompt.

2. In Command Prompt, type the following commands one by one, pressing Enter after each:

• diskpart
• list disk
• select disk X (Replace X with the number of your cloned disk)
• list partition
• select partition Y (Replace Y with the partition that contains your system files)
• active
• exit (exit DiskPart)
• exit (exit Command Prompt)

Note: The partition that contains your system files is usually the small 100MB–550MB System Reserved partition or the C: partition if no System Reserved exists.

3. After exiting Command Prompt, restart your computer. If the partition marking was the issue, Windows should now boot correctly from your cloned drive.

Fix 4: Repair Boot Files (For Both MBR & GPT)

If the cloning tool skipped system partitions, or if boot data became damaged during migration, you can get the no operating system found after cloning error. Here’s how to fix it:

1. Open Command Prompt as mentioned in Fix 3.

2. In Command Prompt, type these commands one by one, pressing Enter after each:

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

3. (Optional) If your system uses GPT + UEFI, you’ll need to recreate the EFI System Partition boot files. In Command Prompt, enter:

• diskpart
• list disk
• select disk X (Replace X with the cloned disk number)
• list partition
• select partition Y (Replace Y with the EFI partition, usually 100–300 MB, FAT32)
• assign letter=Z:
• exit
• bcdboot C:\Windows /s Z: /f UEFI

4. After finishing the repair commands, close Command Prompt and restart your PC. Remove the USB (if you used one) when prompted to boot normally. If the repair was successful, Windows should now load from the cloned drive.

Fix 5: Use Automatic Startup Repair

If manual fixes feel too technical or they simply didn’t work, you can let Windows Automatic Startup Repair handle it for you. Here’s how to run it:

1. Boot from a Windows installation USB. When the Windows Setup screen appears, click Next → Repair your computer.

2. Select Troubleshoot → Advanced options → Startup Repair.

3. Choose the Windows installation on your cloned drive. Windows will now start scanning your drive for boot-related issues and attempt to fix any detected problems.

4. Once Startup Repair finishes, it will display one of two results:

• Repair successful: Your PC will reboot automatically. Remove the USB and let it start from the cloned drive.
• Repair couldn’t fix the issue: You’ll see a report file (e.g., SrtTrail.txt). In this case, proceed with manual fixes like bootrec or bcdboot commands (see previous fix).

Workaround: Re-clone your drive with AOMEI Cloner

If you are tired of trying one solution after another, the best solution is to re-clone your drive using reliable software that ensures all boot-related partitions are copied correctly. AOMEI Cloner is what you need.

Download AOMEI Cloner now to try it out! To copy one hard drive to another, click Clone > Disk Clone and follow the wizard to complete the process.

Verdict

The no operating system found after cloning error can be alarming, but it doesn’t mean your Windows installation is lost. By following the steps in this guide, you can restore your system’s bootability without reinstalling Windows.

If none of the fixes work, re-cloning your disk with a trusted tool like AOMEI Cloner is the most reliable solution. It automatically transfers all necessary boot and system partitions to ensure the cloned drive is bootable. It supports all branded disks. You can use it to clone HDD to WD SSD, Samsung SSD, and Crucial SSD, etc. Why not give it a shot?