Operating System Not Found? Here’s How to Fix It

Dan Price 26-10-2017

Out of all the errors, glitches, and problems The Complete Windows 10 Fall Creators Update Troubleshooting Guide Have you run into a Windows 10 Fall Creators Update bug? You found the right place to look for fixes. Here are the solutions for the most common problems. Read More you might encounter while using Windows 10, few generate as much fear as the dreaded “Operating system not found” screen.


Visions of losing your entire media collection flash before your eyes, students weep at the thought of irretrievable essays and assignments, and professionals worry about what their boss will say when they learn months of project work has vanished.

operating system not found error fix

Stop. Take a deep breath. Your data is still there The Best Free Data Recovery Tools for Windows Data loss can strike at any time. We will highlight the best free data recovery tools for Windows to help get your precious files back. Read More — and just as importantly, you can fix the problem. In this article, we’re going to show you the available solutions. There are six in total, so go through them slowly until you find the one that works for you.

Without further ado, here’s how to fix the “Operating system not found” message on Windows 10.

1. Check the BIOS

You need to check for two things in the BIOS. Firstly, you need to ensure your machine recognizes your hard drive. Secondly, you need to make sure the drive on which you installed Windows is listed as the preferred boot drive.


The methodology for entering the BIOS How to Enter and Reset the BIOS to Default Settings on Any Computer If your computer won't boot, the BIOS may be to blame. Here's how to enter it and reset it to the factory defaults to fix those problems. Read More changes from manufacturer to manufacturer. Typically, you’ll need to press Escape, Delete, or one of the Function keys. You should see an onscreen message advising you which is the correct key.

The BIOS menu The BIOS Explained: Boot Order, Video Memory, Saving, Resets & Optimum Defaults Need to change your PC's boot order or set a password? Here's how to access and use the BIOS, and some commonly modified settings. Read More itself also varies between devices. Broadly speaking, you need to locate the Boot tab along the top of the screen. (You can only use your keyboard to navigate the BIOS menu.)

Within the Boot tab, highlight Hard Drive and press Enter. Do you see the name of your hard drive? If so, keep reading.

Next make sure Hard Drive is listed above USB Storage, CD\DVD\BD-ROM, Removable Devices, and Network Boot. You can adjust the order using the + and keys.


If everything in your BIOS menu looked fine, jump to step three. If you didn’t see the hard drive listed, go to step two.

2. Reset the BIOS

If your machine is not recognizing your hard drive, there are lots of possible causes. For non-tech-savvy users, the only easy solution is to try resetting the entire BIOS menu to its default values.

At the bottom of the BIOS menu, you should see a key for Setup Defaults or Reset BIOS. On my machine it’s F9, but it might be different on yours.

Confirm your decision when prompted and restart your machine.


If the operating system is still not found, you can stop reading this article. Unless you know a lot about building computers, you’ll need to take your machine to a computer repair shop.

3. Fix the Boot Records

Windows primarily relies on three records to boot your machine. They are the Master Boot Record (MBR), DOS Boot Record (DBR), and the Boot Configuration Database (BCD).

If any of the three records becomes damaged or corrupted, there’s a high chance you’ll encounter the “Operating system not found” message.

Thankfully, fixing these records is not as complicated as you might think. You just need a removable Windows installation drive. Use Microsoft’sMedia Creation Tool to create Windows 10 installation media How to Create Windows 10 Installation Media Regardless of how you arrived at Windows 10, there's a way to create your own installation media. Sooner or later you might need it. Let us show you how to be prepared. Read More .


When your tool is ready, you need to use it to boot your machine. Depending on your device, you might only need to press a single key during the boot process, or you might have to change the boot order in the BIOS menu.

Eventually, you will see the Windows Setup screen. Enter your preferred language, keyboard, and time format, and click Next. On the next screen, select Repair your computer in the bottom left-hand corner.

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Next, navigate to Troubleshoot > Advanced Options > Command Prompt. When Command Prompt loads, type the following three commands. Press Enter after each of them:

  • bootrec.exe /fixmbr
  • bootrec.exe /fixboot
  • bootrec.exe /rebuildbcd

Each command might take several minutes to complete. Once all the processes are finished, restart your PC and see if it boots successfully.

4. Enable or Disable UEFI Secure Boot

Almost every Windows machine is shipped with UEFI firmware and Secure Boot enabled How to Check If Your PC Uses UEFI or BIOS Firmware Sometimes when troubleshooting, you'll need to know whether your PC uses UEFI or BIOS. Here's how you can check with ease. Read More . However, in some cases it might not work.

For example, if Windows is installed on a GUID Partition Table, it can only boot in UEFI mode. Conversely, if Windows 10 is running on an MBR disk, it cannot boot in UEFI mode.

operating system not found error fix

As such, it’s prudent to either enable or disable UEFI Secure Boot and see if it makes a difference.

You make the adjustments in the BIOS menu. Usually, the option will be called Secure Boot and can be found in the Security tab.

5. Activate the Windows Partition

It’s possible that the partition which Windows is installed on has become disabled. You can fix it using Windows’ native diskpart tool.

To work through the following steps, you will once again need a Windows installation media USB.

Turn on your machine and boot from the tool. As in step three, you’ll need to enter your language preferences, etc. then click Next, then select Repair your computer. Go to Troubleshoot > Advanced Options > Command Prompt.

operating system not found error fix

In Command Prompt, type diskpart and press Enter, then type list disk and press Enter. You will see a list of all the disks attached to your machine. Make a note of the disk number you need. Typically, it’s the largest one.

Next, type select disk [number], replacing [number] with the aforementioned number. Press Enter.

Now type list volume and press Enter. It will show you all the partitions on the disk you selected. Establish which partition Windows is installed on and make a note of the number, then type select volume [number], again replacing [number] with the number you just noted.

Finally, type active and press Enter.

To see if the process was successful, restart your machine.

6. Use Easy Recovery Essentials

Easy Recovery Essentials is a third-party app that specializes in fixing boot issues. If none of the previous five steps have worked, it’s worth trying.

In addition to fixing the “Operating system not found” message, it can also solve other common startup error messages. They include INACCESSIBLE_BOOT_DEVICE, INACCESSIBLE_BOOT_VOLUME, UNMOUNTABLE_BOOT_VOLUME, BOOTMGR is missing, The Boot Configuration Data for your PC is missing or contains errors, An error occurred while attempting to read the boot configuration data, boot.ini not found, and more.

Just download the app, burn the ISO to a CD, and use the CD to boot your machine. The app’s wizard guides you through the repair process. The software costs $19.75.

Did You Fix the Error Message?

Hopefully, one of these six solutions will work for you. If all else fails, try taking your computer to a dedicated computer repair shop.

Have you encountered the dreaded “Operating system not found” message? What did you do to fix it? Did you use one of the solutions we covered or did you come with your own technique?

Related topics: BIOS, Data Recovery, Troubleshooting, UEFI, Windows 10.

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  1. Ankit
    November 10, 2019 at 1:34 am

    Very very thanks.

    • Mani
      January 7, 2020 at 5:57 am

      I habe a problem with my pc an operating system was nt found

  2. Tom
    November 8, 2018 at 7:03 am

    I leave my Vaio laptop running 24/7. The other day I woke up to the dreaded "Operating System Not Found" error message (or I'd like to call Black Screen of Death). This article didn't help me because I can't even access the BIOS screen (it uses UEFI) -- upon turning on the laptop it instantly shows the error.

  3. manu
    April 25, 2018 at 12:35 am

    If you have used Easeus Partition master as I did unfortunately, try Macrium Reflect free edition. Macrium worked miracles for me. maybe you. It took about three hours to clone my 200Gb hdd to ssd. and only the windows partition since my original drive was larger.

  4. Jakir hossain
    April 2, 2018 at 3:19 pm

    My laptop bois menu could not open anyway.
    Then I entered password from this site
    Here I searched bios password according to my "system disabled " code .
    Apply some one and bios menu has opened.
    But I saw that accessing the menu was troubled to move like hanged.

    However, onetime I got to access the boot option and here I pressed f9 and find "default boot setup" and then pressed "yes" .

    And then pressed f10.

    Then laptop starting to load but showing "operating system not found" again.

    1. How to fix it?.
    2. Do I need to reset bios password?.if not is resented will it make any problem?to reset which are the options?
    3. My hard drive was not found when I tryed to setup newly windows when I first faced "operating system not found".

    In the bios section I saw that " sata drive is ide on set.
    In the security option want to set up new password is it important to apply or not?.
    I don't found in the boot option the legacy only menu.
    I selected one to another and clucked enter in the boot option but did not find the "legacy only" set up menu.

    I pressed f9 and "default boot option" was visible to set and I pressed "yes". And then pressed f10.

    Then laptop start to loading newly but showing " operating system not found " again.

    Please, tell me the solution for this.
    Tnx bro.

  5. Jakir hossain
    April 2, 2018 at 3:03 pm

    Help me please, howcto fix it.I did press f9 on boot option and clicked on default boot setting >yes .then pressed on f10. After pressing it laptop showing operating system not found again.
    How to fix it?

  6. L.
    October 26, 2017 at 9:15 pm

    Ten Days ago with my ASUS Windows 10 Laptop I got an even scarier error.
    Instead of going into windows it told me: "autochk program not found - skipping AUTOCHECK"
    After that it went to the troubleshoot section and did the same you told to do (rebuild the partition) to no avail.

    With the neccescary tools at hand I looked on the harddisk. Everything was there - just didn´t boot.

    I looked for the error message at google - only 8(!) findings which were not helpfull at all.

    So I gave the machine a new Windows OS (with my personal data NOT destroyed) which worked flawless.

    Before and after I tested for virus or similar things. No such thing.

    I´m still puzzeld what happended to my laptop.

    • KwaK
      October 27, 2017 at 2:24 pm

      I had to fix a laptop with a similar, but even worse situation - I received a laptop that I helped fixing, which had the contents of the system disk simply "vanish" (the drive showed up as unformatted). After a BSOD the system wouldn't boot, obviously - because there were no longer any bootable devices present. Why it happened is still a mystery and the laptop owner swears they were only writing up a college paper and I lean to believe they aren't actively dabbling with *free* software (aka "cracked" ones from downloaded torrents), which makes it even more mysterious. I restored the data from a backup and returned it to the puzzled owner. My wild guess is that it was a result of some virus as well, perhaps a cryptovirus and the antivirus software stopped it before it could encrypt and permanently destroy data.

  7. Al Sorrell
    October 26, 2017 at 5:00 pm

    I tried to use Easy Recovery Essentials about 2 weeks ago - it wouldn’t even run on my Ryzen CPUMSI MB. Email support only and was not particularly helpful. I finally did an image restore and working with PayPal to get a refund