Quite a few Windows users have found that, after they reset or refreshed their Windows 10 computer and it froze in the middle of the process forcing them to reboot, they were greeted by a blue screen displaying an error message stating, “An operating system wasn’t found. Try disconnecting any drives that don’t contain an operating system. Press ctrl+alt+del to restart.” This is quite shocking because resetting or refreshing a Windows 10 computer does not delete its operating system. Consequently, this blue screen should not be displayed at all. In such cases, the computer continues to display this blue screen regardless of how many times the user reboots. Many users have also experienced this same issue after downloading and installing updates for their Windows 10 computer.
The most probable culprit behind this problem is the corruption of system files critical to the proper functioning of Windows. If anything damages your computer’s system files, you may find yourself looking at a blue screen that says your computer has no operating system whatsoever after you reboot. The following are the two methods that you can use to fix this problem:
Method 1: Try performing a factory reset on your computer
Most computers come with a recovery partition on their hard drives right out of the box. This is a factory-installed hard drive partition that contains all the necessary data to reset your computer to its factory settings without requiring any additional materials, such as a recovery disk. Factory resetting your computer has a good chance of resolving the blue screen issue that indicates your computer lacks an operating system. However, it’s important to note that factory resetting your computer will erase all of the data stored on your computer’s C drive. Also, you can only perform a factory reset if you haven’t deleted the recovery partition.
The process for factory resetting a computer to which you cannot log on, using its Recovery partition, varies from one computer to another. Therefore, you might need to conduct some research on how your specific brand and model of computer can be factory reset. For example, if you want to factory reset an ASUS computer using its Recovery partition, you would need to:
Turn the computer off.
Power the computer on”
Repeatedly press F9 as soon as the computer starts booting up.
Press Enter to select the Windows Setup (EMS Enabled)
Follow the onscreen instructions and click on Next in the two windows that follow.
Select the Recover Windows to first partition only option and click on Next. Choosing this option will ensure that only drive C of your computer is formatted and the data on all the other drives is left untouched.
Follow the onscreen instructions to go through with the factory reset process.
Method 2: Perform a clean install of Windows 10
If factory resetting your computer doesn’t work, or if for some reason you can’t use the Recovery partition, your only remaining option is a clean install of Windows 10. Be aware that a clean installation will remove all applications, data, and settings from your computer. However, this shouldn’t pose a problem in this case, as the alternative is a computer without an operating system. To perform a clean install of Windows 10, you need to follow these steps:
On another Windows computer, go here and download the media creation tool by clicking on Download tool now,
Install the media creation tool.
Open the media creation tool.
Select for another PC.
Follow all the on-screen instructions, such as selecting your preferred language and the system architecture (32-bit or 64-bit) of the computer onto which you are downloading the Windows 10 setup. Then, download an ISO file for Windows 10. You can use this file not only to install Windows 10, but also to burn it to a USB or DVD.
Boot up the computer suffering from the blue screen that indicates it does not have an Operating System, then access its BIOS or UEFI settings and change the boot order so that it starts from a USB. Save the changes, exit the BIOS, insert the USB containing the Windows 10 setup, and then shut down your computer.
Power your computer up. It will boot from the USB that you inserted, so press any key to get the computer to start installing Windows 10.
Enter your language and other preferences, then click on ‘Install Windows’. Enter your product code or click on ‘Skip’ in the next window if the copy of Windows 10 you were using before was already registered. Agree to the license terms and choose a Custom installation. Select the partition where you wish to install Windows 10 and format it. Then, click on ‘Next’ and follow the rest of the installer’s instructions to successfully perform a clean install of Windows 10 on your computer. After a fresh install of Windows 10, you will no longer see a blue screen stating that your computer does not have an operating system every time you restart it.
Also see how to create a Bootable ISO using Rufus.