The 'Operating System Not Found' error is a common issue that can prevent your computer from booting, leaving your files and applications inaccessible. This guide provides practical, step-by-step solutions to resolve the problem. By following this guide carefully, you can restore access to their system without losing important data.
Operating System not found error with NVMe and HDD
Today when I started up my computer, I was greeted by a black screen saying "Operating System not found". I have 2 storage devices, an NVMe which is screwed onto the motherboard and it is has Windows 10 on it, and an HDD which is connected by a cable. I tried unplugging the HDD from the motherboard and the power supply. Once I did that, I turned it on and it said something about reconnecting a drive. I tried re-plug it in and it gave me the same problem as the first time. Any ideas or help would be appreciated.
- Question from Hazz
The "Operating System Not Found" error appears when a Windows 10 or 11 PC fails to detect a valid operating system during startup. This issue can occur after a system crash, accidental changes to BIOS settings, hard drive corruption, or boot sector damage. When this error appears, users are unable to access their desktop, files, or applications, effectively rendering the computer unusable until the problem is resolved.
This guide walks you through practical, step-by-step methods to fix the "Operating System Not Found" error on Windows. By following these instructions carefully, users can restore their systems efficiently, minimize data loss, and ensure the computer boots normally again.
Identifying the root cause helps determine whether a quick BIOS adjustment, hardware reconnection, or a more advanced repair (like rebuilding the boot sector) is needed. The following causes can trigger the "operating system not found" error:
📌 Incorrect Boot Order in BIOS/UEFI: If the system tries to boot from a device without an operating system, Windows cannot load.
🔌 Disconnected or Failing Storage Devices: Loose cables, damaged connectors, or failing drives can prevent the system from detecting the OS.
✂️ Corrupted Master Boot Record (MBR) or Boot Sector: Damaged boot information can make Windows invisible to the startup process.
📂 File System or Partition Corruption: Critical system partitions may become unreadable due to sudden shutdowns, malware, or disk errors.
💾 Recent Hardware Changes: Adding or removing drives, upgrading storage, or modifying the motherboard may lead to boot issues if BIOS settings are not updated.
⚙️ Virus or Malware Infection: Certain malicious software can overwrite or damage boot files, preventing Windows from loading.
When your PC shows the "Operating System Not Found" error, the cause can range from simple BIOS misconfigurations to corrupted boot files. The following solutions are organized from quick fixes to more advanced repairs, allowing you to address the issue efficiently without unnecessary risk.
Sometimes, the system attempts to boot from USB drives, SD cards, or external HDDs that have no operating system, triggering the "not operating system found" error. Disconnecting all external devices ensures the PC looks for the correct boot drive.
Step 1. Unplug all external drives, USB devices, SD cards, and other media.
Step 2. Press "Ctrl" + "Alt" + "Del" to restart your computer and check if Windows boots normally.
A common cause of Windows boot failure is a disconnected or loose cable between the motherboard and storage devices. Verifying the physical connections ensures that the BIOS can detect the drive containing Windows.
Step 1. Power off the PC and unplug it from the wall.
Step 2. Open the case and check that SATA, power cables, or NVMe connectors are securely attached.
Step 3. Close the case and power on the PC to test booting.
A failing drive can prevent Windows from being detected. Checking the drive's status can indicate whether recovery or replacement is needed.
Step 1. Restart the computer and repeatedly press F2, F10, or Del (depends on your computer brand) to enter BIOS/UEFI. Verify if the Windows drive can be detected in BIOS/UEFI.
Step 2. If available, you can run the built-in diagnostics tool like HP Hardware Diagnostics to check the hard drive health.
Step 3. If errors are found, you may need to replace the failed hard drive with a new one for stable performance.
Windows includes a built-in repair tool that can automatically fix boot issues, including corrupted or missing system files. This method is safe and often resolves the problem without reinstalling the OS.
Step 1. Create a Windows 10/11 installation media if you don't have one.
Step 2. Boot from the USB/DVD installation media and select "Repair your computer" instead of "Install now".
Step 3. Navigate to "Troubleshoot" > "Advanced options" > "Startup Repair".
Step 4. Select your Windows installation and follow on-screen instructions to try to fix the "not operating system found" error.
If the system partition is inactive, the BIOS fails to locate and run the boot files on the partition, resulting in system boot failure. Setting the correct partition as active ensures the bootloader is properly recognized.
Step 1. Boot into WinRE from Windows installation media and open "Command Prompt" from "Advanced Options".
Step 2. Enter the following command to active your system partition:
Step 3. After the process is completed, enter "exit" to close Command Prompt and restart your computer to check if the error is still here.
Corrupted BCD prevents Windows from loading correctly. Rebuilding it can restore the bootloader configuration without affecting personal files. Follow these steps:
Step 1. Boot into WinRE and open Command Prompt via installation media.
Step 2. Run the following commands one by one and hit "Enter" after each one:
Step 3. Restart the computer and check if Windows works normally.
If none of the above solutions work to fix the "operating system not found" error on Windows. Even with healthy drives, an incorrect BIOS/UEFI boot order can cause this error. Ensuring the correct drive has top priority to boot allows the PC to find Windows first.
Step 1. Restart your computer and press F2, Del, or F12 (according to your computer brand) repeatedly to enter BIOS/UEFI.
Step 2. Navigate to the "Boot" menu and locate the boot priority list.
Step 3. Set your system drive as the top priority and save the changes, then try to boot your computer and check the error.
Some systems may not boot due to conflicts with Secure Boot settings, especially after hardware changes or drive cloning. Secure Boot can block drives with certain boot signatures. Toggling this setting can help the BIOS recognize the system drive.
Step 1. Enter BIOS/UEFI as described earlier and locate "Secure Boot" or "Boot" settings.
Step 2. Highlight it and toggle it (enable or disable depending on your current setup) and save changes.
Step 3. Try booting your system again to check if the laptop "operating system not found" continues.
Resetting BIOS restores default settings and clears misconfigurations that may prevent boot detection. This is a safe troubleshooting step before reinstalling Windows.
Step 1. Enter BIOS/UEFI like mentioned above and locate the option to "Load Setup Defaults" or "Reset to Default".
Step 2. Confirm and save the changes, then restart the computer to see if it boots properly.
If all previous methods fail to resolve the "operating system not found" error, the operating system may be severely corrupted. Reinstalling Windows ensures a clean boot environment while replacing corrupted system files. This solution can help you reinstall Windows without any data loss.
Step 1. Get into the WinRE with a Windows installation or recovery media like mentioned earlier.
Step 2. Select "Troubleshoot" > "Reset This PC". This restores your PC to factory reset and eliminates errors like missing operating system.
Step 3. Choose "Keep my files" to reserve all your personal files in the C drive. But the applications and settings will be deleted.
Step 4. Select "Cloud download" or "Local reinstall" based on your needs.
Step 5. Confirm the reset settings and "Next" to continue the process. You can check the affected programs by clicking on "View apps that will be removed".
Step 6. Click "Reset" to start the process.
Even after trying all the steps above, there are situations where Windows still fails to start, and the data on the system drive remains inaccessible. In such scenarios, using a dedicated data recovery solution designed to work with unbootable drives is the safest approach. MyRecover is one such professional recovery tool that can scan drives even when Windows cannot boot.
It allows users to recover lost files from formatted, corrupted, or inaccessible partitions without requiring the operating system to start completely. With it, you can safely extract critical documents, photos, and other data before attempting to reinstall Windows.
Step 1. Download and install MyRecover on a bootable computer. Prepare a blank USB drive to make bootable media and insert it into the PC.
Step 2. Run the program and select "PC Crashed Recovery" tab, click "USB Boot Device" and click "Create" to start the process.
Step 3. Back up important data on the USB first, as the drive will be formatted. Wait until the bootable drive creation finishes.
Step 4. Connect it to the computer with "operating system not found" error and enter BIOS/UEFI to change the boot order as the USB drive. Then, boot it from the bootable drive.
Step 5. It will automatically enter the interface of MyRecover. Select the system drive and click "Scan" to search for recoverable files.
Step 6. Browse the scan results and select the desired files, then click "Recover". You can extract all files from the drive by selecting the "Existing files" folder.
Step 7. Choose a safe drive (preferably an external hard drive) to save the recovered files to avoid overwriting original files.
When the process is done, you can check the recovered files in the destination drive on a working computer.
The "Operating System Not Found" error can disrupt access to your Windows 10 or 11 PC, but following the troubleshooting approaches in this guide can restore your system efficiently. From simple fixes like checking BIOS settings and reconnecting drives to advanced steps such as rebuilding the boot configuration or reinstalling Windows, each solution targets a specific potential cause.
In cases where the system still cannot boot, prioritizing data recovery is essential. Tools like MyRecover enable safe extraction of files from unbootable or corrupted drives, ensuring that critical data remains intact before further repairs. By upgrading to the Technician edition, you can also share this powerful data recovery tool with your family, friends, or colleagues under a single license.
Q1: How do I fix an operating system not found?
Start by checking the BIOS/UEFI to ensure the correct boot drive is selected. Verify internal drive connections and run Windows Startup Repair using installation media. If needed, rebuild the boot configuration data (BCD) or reactivate the system partition to restore boot functionality.
Q2: Is the black screen of death fixable?
Yes. The black screen may be caused by corrupted boot files, display issues, or hardware failures. Boot into Safe Mode, run Startup Repair, or check hardware connections. For severe system corruption, a Windows reinstall may be required to restore functionality.
Q3: How do I restore my operating system?
Use Windows Recovery Environment (WinRE) via installation media. Navigate to "Troubleshoot" > "Reset this PC" or "Advanced Options" to repair startup issues. Choose "Keep my files" to retain personal data while reinstalling system files.
Q4: How to tell if a computer is bricked?
A bricked computer fails to power on or boot, showing no BIOS/UEFI screen or response. If the system doesn't reach the POST screen despite power checks, display tests, and hardware reseating, it may be considered hard-bricked.
Q5: How to fix no valid operating system found?
Check BIOS boot order and confirm the OS drive is recognized. Run Startup Repair, reactivate the system partition, or rebuild the BCD. If the drive is damaged, test for disk failure and recover data before reinstalling Windows.
Q6: Is there any way to fix the black screen of death?
Yes. Troubleshoot by booting into Safe Mode or WinRE, updating or rolling back drivers, running Startup Repair, and checking for hardware issues. Severe cases may require system restore or reinstalling Windows to recover a usable system.