Despite the alarming error notice "Operating system not detected," your data is still present. Find out how to solve this peculiar issue!
How to fix Operating System Not Found Problem on Windows
The dreaded "Operating system not found" box is one of the errors, bugs, and issues you could run into when using Windows 10. Few of them cause as much anxiety as it does. You have visions of losing your whole media library, your job, and your priceless images.
Stop. Breathe in deeply. Your data is still available, and more importantly, you can resolve the issue. Let's look at how to resolve Windows 10's "operating system not found" problem.
1. Check the BIOS
In the BIOS, you must look for two items. To begin with, make sure your computer can detect your hard disk. The disk on which Windows was installed must be listed as the preferred boot drive, which is the second thing you must check.
The procedure for accessing the BIOS varies depending on the manufacturer. Normally, during boot-up, before Windows loads, you'll need to use Escape, Delete, or one of the Function keys. During the startup process, you should receive an onscreen notification instructing you on which key to press.
Additionally, different devices have different BIOS menus. In general, look for the Boot tab towards the top of the screen. Keep an eye out for a list of controls on the BIOS screen as you can only explore the BIOS menu using your keyboard.
Press Enter after selecting Hard Drive in the Boot tab. A hard drive should always be mentioned before USB Storage, CD/DVD/BD-ROM, Removable Devices, and Network Boot. The + and - keys can be used to change the order.
Go directly to step three if your BIOS menu shows everything to be in order. If the hard disk wasn't mentioned, move on to step two.
2. Reset the BIOS
There are several potential reasons why your computer may not be detecting your hard disk. The only simple fix for non-technical people is to attempt to reset the whole BIOS menu to its default defaults.
You should notice a key for Setup Defaults or Reset BIOS at the bottom of the BIOS menu. It's F9 on some computers, but it could be something else on yours. Restart your computer after confirming your choice when asked.
You can stop reading this article if the operating system is still not detected. You'll need to bring your device to a computer repair shop unless you have extensive knowledge of computer construction.
3. Fix the Boot Records
Three files are generally used by Microsoft Windows to start your computer. They are the Boot Configuration Database, the DOS Boot Record, and the Master Boot Record (BCD).
You are likely to get the "Operating system not found" warning if any of the three records is damaged or corrupted.
Thankfully, it's not as difficult as you would imagine to correct these records. Simply a detachable Windows installation disk will do. Create some installation discs for Windows 10 using Microsoft's Media Creation Tool.
You must use your tool to start your computer when it is ready. You might simply need to press a single key to start your device, or you could need to modify the boot sequence in the BIOS menu.
You will eventually come across the Windows Setup screen. Click Next after selecting your chosen language, keyboard, and time format. Select Repair your computer on the following screen.
Then select Command Prompt under Troubleshoot > Advanced Options. Type the next three instructions once Command Prompt has loaded. After each of them, hit Enter:
- bootrec.exe /fixmbr
- bootrec.exe /fixboot
- bootrec.exe /rebuildbcd
It might take many minutes to execute each instruction. When every procedure is complete, restart your computer and check to see whether it boots properly.
4. Enable or Disable UEFI Secure Boot
Almost all Windows machines come pre-configured with Secure Boot enabled and UEFI firmware. However, it might not work in all circumstances. For instance, Windows can only boot in UEFI mode if it is installed on a GUID Partition Table. On the other hand, Windows 10 cannot boot in UEFI mode if it is installed on an MBR drive.
In order to determine whether UEFI Secure Boot should be enabled or disabled, it is wise to try both. The BIOS menu is where you make the settings. The option is often under the Security tab and is titled Secure Boot.
5. Activate the Windows Partition
The Windows partition can be inaccessible. The diskpart tool that comes with Windows can be used to remedy this. You will once more require a Windows installation media USB to complete the next stages.
Start your computer by booting from the tool. You must input your language choices, among other information, click Next, choose Repair your machine, and then pick Troubleshoot > Advanced Options > Command Prompt.
Enter the commands diskpart and list disk into the Command Prompt window. A list of all the disks connected to your computer will be shown for you. Make a note of the required disk's number. Usually, it's the biggest.
Replacing [number] with the aforementioned number, type pick disk. Enter the key.
Type list volume now and hit Enter. You will be shown every partition on the chosen disk. Make a note of the partition number where Windows is installed, then locate the volume choose volume [number], substituting [number] once more with the partition number you just recorded.
Type "active" and hit the Enter key to finish. Restart your computer to see whether the operation was successful.
6. Use Easy Recovery Essentials
A third-party program called Easy Recovery Essentials is adept at resolving boot-related problems. It's worthwhile to attempt if none of the first five stages have been successful.
It can resolve other typical starting problem messages in addition to the "Operating system not found" message. They consist of:
- 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
Simply download the application, create a CD from the ISO, then boot your computer from the CD. The wizard in the app walks you through the repair procedure.
7. Reinstall your Windows
If none of the aforementioned solutions have been successful so far, a complete reinstallation may be necessary. You won't lose any of your data, so don't worry. Now that your PC won't start, you must reinstall Windows directly from a USB device, as instructed by Microsoft.
So, insert your bootable USB device and use it to start your PC. If you don't already have a bootable USB, you may get started by reading our tutorial on making one from scratch. If Windows won't start, you might first need to rearrange the boot sequence so that the operating system can load and boot up through your USB. Press Esc, F10, F12, or the appropriate key to boot into the boot-selection device to achieve that. Change the booting order to boot from your USB after you've arrived.
From then, the procedure is quite simple. Simply follow the on-screen prompts to start the installation procedure, then wait while Windows is installed.
As a last option, visit a store
In all but the most extreme cases, this advice should enable you to resolve the operating system not found problem on Windows 10. But regrettably, it's only one of several error messages you could see when using the Microsoft operating system.
It makes little sense to keep playing with your machine if you can't figure out what's wrong with it. If you lack technological know-how, you could cause more harm than good. As a last option, visit your neighborhood PC repair shop; they ought to be able to get you back online quickly.