Why does my computer say no Operating System found Windows 10?

Seeing the error message “no operating system found” can be frustrating when trying to boot your Windows 10 computer. This typically indicates that the operating system cannot be detected by the computer’s boot loader. There are several potential causes for this issue that can range from simple to complex. In this comprehensive guide, we will explore the common reasons why you may encounter this error along with solutions to help get your system up and running again.

What Does “No Operating System Found” Mean?

The “no operating system found” error occurs during the boot process before Windows has loaded. When you power on your computer, the first thing that runs is the BIOS or UEFI firmware. This built-in software performs a power-on self test (POST) to ensure the hardware components are operational.

Next, the boot loader takes over to load the operating system. If the boot loader cannot detect a valid operating system, you will see an error message stating “no operating system found” or something similar like “operating system not found.”

This indicates that critical boot files are corrupted or missing on the system drive preventing the operating system from loading properly. Without the boot files, the computer does not know where to look to find and start Windows 10.

Common Causes

There are many different reasons why your computer cannot locate the Windows 10 operating system boot files. Here are some of the most common causes for the “no operating system found” error:

Corrupted System Files

Corrupted system files are one of the most frequent causes of the “no operating system found” error. Key boot files like bootmgr and winload.exe can become damaged from improper shutdowns, hard drive errors, or malware/virus infections. If these critical system files are corrupted, the boot process cannot complete properly.

Some of the system files that could be corrupted include:

  • Bootmgr
  • Winload.exe
  • Winload.efi
  • Ntldr
  • Ntdetect.com
  • Bootcfg.exe

If the Master Boot Record (MBR) has errors or inconsistencies, it can also prevent the OS from loading and trigger this issue. The MBR contains information on the partitions and boot loader, so any damage can impact the ability to start Windows.

Hard Drive Issues

Since the operating system files and boot files reside on the primary hard drive, any problems with the hard drive can also cause the “no operating system found” message. Issues like bad sectors, a damaged file system, connection problems, or even an outright hard drive failure can prevent access to the necessary boot files.

Some signs of a hard drive problem include:

  • Unusual noises from the hard drive
  • Long loading times
  • Files missing or corrupted
  • Frequent crashes and freezes

If you suspect a problem with the hard drive, it’s a good idea to run disk checking and diagnostic utilities. Replacing the hard drive may be necessary if it is severely damaged or not detected at all.

Boot Order Changes

An incorrect boot order could render your OS undetectable. The boot order determines the sequence of storage devices that the computer checks when looking for an operating system. If the hard drive with Windows installed is not listed first, you may get the “no operating system found” message.

Some things that can alter the boot order include:

  • Adding or removing drives
  • Enabling USB or optical drives as bootable devices
  • Changing the BIOS settings

You will need to check the boot order in the BIOS and move the proper hard drive to the top of the list to fix this.

Damaged or Loose Cables

It may seem obvious, but sometimes all it takes is a damaged or loose SATA cable to cause the operating system to not be detected.

If the cable connecting the hard drive to the motherboard is damaged or has become disconnected, the BIOS may not be able to see or access the drive correctly.

Reconnecting the SATA cable properly or swapping it out for a new cable often resolves the issue if that is the only problem.

Fixes and Solutions

Now that you know what might cause the “no operating system found” error, here are some steps to troubleshoot and fix the problem so you can boot Windows 10 again:

Automatic Repair

If you can access the advanced startup options in Windows 10, you can use the Automatic Repair feature to fix boot issues. Here is how to try Automatic Repair:

  1. Access the Windows Recovery Environment by rebooting and selecting Troubleshoot > Advanced options.
  2. Go to the Startup Repair option. This will load automatic repair and scan for problems.
  3. Allow Automatic Repair to run when prompted. It will attempt to replace damaged system files and repair issues.
  4. Restart when it finishes. In many cases, Startup Repair can fix the operating system not found error by repairing boot files.

System File Checker

If you can access the Command Prompt from the Advanced Startup options, you can check system files using the System File Checker (SFC) tool:

  1. From the Recovery options, choose the Command Prompt.
  2. When the command prompt opens, type sfc /scannow and hit Enter.
  3. This will scan Windows system files and replace corrupted ones.
  4. After it completes, reboot and see if the error is resolved.

Running SFC can often fix the issue by restoring damaged system files it detects.

Startup Repair from Install Media

If the built-in Startup Repair did not resolve the issue, you can try the Startup Repair tool from a Windows 10 installation disc or bootable USB. This works offline outside the installed OS.

To use the Startup Repair from install media:

  1. Boot from the Windows 10 disc or USB drive.
  2. Choose your language and click Next.
  3. Click Repair your computer on the lower left.
  4. Select Troubleshoot > Advanced options > Startup Repair.
  5. Startup Repair will run and try to automatically diagnose and fix boot errors. Allow it to complete.

Using the Startup Repair this way often resolves the issue when the built-in repair could not.

System Restore

If you can boot into Windows 10 Safe Mode, you can try using System Restore to roll back system files and settings to an earlier restore point before the issues occurred.

To restore from a previous point:

  1. Boot to Safe Mode with Command Prompt.
  2. At the command prompt, type rstrui.exe and hit Enter.
  3. Choose a restore point that preceded the “no operating system found” issue.
  4. Allow System Restore to complete and restart when prompted.

This may fix the boot error if it was caused by a recent system change or corrupted files.

Repair or Replace Hard Drive

As mentioned previously, hard drive problems are a common reason for this error. If you think the hard drive is damaged, try scanning it for errors using CHKDSK /f or a diagnostic utility like SeaTools.

If the drive has developed bad sectors or other issues that cannot be repaired, replacement of the hard drive may be required to get your system booting again. Cloning the old drive to a new, healthy drive can help preserve your files and OS installation.

In some cases, initializing a new hard drive and performing a fresh OS installation may be the solution if drive replacement does not work or is not feasible.

Check connections and cables

It’s worthwhile to open up the computer and check that all hard drive and data cables are properly plugged in. Remove and re-seat the cables connecting the hard drive to the motherboard. Also check power cables to ensure the drive is receiving power.

Damaged SATA cables can cause connection issues so try swapping in a new SATA data cable if you suspect a faulty cable. Loose connections or cables can sometimes cause intermittent detection of the hard drive and system files.

Adjust BIOS boot order

Access your computer’s BIOS settings and confirm the boot order lists the proper hard drive containing the OS as the first boot device. If the hard drive is not at the top of the list, use the boot menu to rearrange it to the first priority position.

Also make sure no other devices like USB drives or optical drives are set as higher priority than the system hard drive in the boot sequence.

Reinstall Windows 10

If all else fails and no hardware issues are found, reinstalling Windows 10 can be an option. Back up your data first, then boot from install media to erase the drive and perform a clean OS installation.

This will erase your files and programs, but can resolve a “no operating system found” problem caused by corrupt system files that prevents the OS from loading.

Be sure to try other troubleshooting steps before a full reinstallation if possible to avoid data loss. But a fresh Windows 10 install is often a reliable fix when diagnosing the exact cause is difficult.


The “no operating system found” error when attempting to boot into Windows 10 is usually repairable. In many cases, automatic repair options like Startup Repair can identify and replace damaged system files to successfully boot the OS. For hardware issues, replacing defective hard drives or cables may get Windows loading again.

Reinstalling Windows is an option if startup repairs cannot resolve any system file corruption. Checking boot order settings and connections can also help troubleshoot boot issues. With the right repairs or replacements, you should be able to resolve the operating system not found error in most situations.

Cause Solution
Corrupted system files Startup Repair, SFC scan, System Restore
Hard drive issues Run CHKDSK, replace hard drive
Boot order incorrect Re-arrange boot order in BIOS
Loose cables Reconnect cables, replace faulty cables