Missing Operating System means that the operating system has suffered a mishap, so you have technically run out of operating system (this happens regardless of the version of Windows you use).
This happens when, in some way, you move the files from a folder protected by the operating system, either when Windows is updating and installing and the computer shuts down unexpectedly, or when you change the settings established in the BIOS of your computer.
This is a fatal error for many users. As soon as they see the message "Missing Operating System" on their computer screen they know that they have probably run out of operating system; therefore without your precious information.
What is the real reason why this error happens to us? The answer is not easy to give, because even Microsoft has not yet been able to find the reason that generates it. One of the possible causes may be incompatibility between the hardware and the software being installed.
It can also be generated when an error occurs during the installation of a Microsoft Windows update (between 75% to 90%, according to users). A change of access to the hard disk where the BIOS is located (modification of the initial configuration of the motherboard) may also affect.
Lastly, this error may have been caused by sudden changes within the Windows root directory. It can be fixed? Yes. You can contact an expert on the official Microsoft website, and you can see the following recommendations, which you should follow to the letter (we are not responsible for their misuse).
How to solve it?
If what you did was only a change in the path that determines where the hard drive is, and perhaps you configured the system so that the computer would boot from a pendrive, CD-ROM / DVD or another hard drive (which is not where the operating system), you can see the following steps where we explain how to solve this error.
Change BIOS settings
Before proceeding further you should know that the BIOS is the one in charge of starting and verifying that all the components of your computer (hardware) are working properly. The name BIOS stands for Basic Input Output System.
To verify it, you are going to turn on your computer.
As soon as you turn it on you will see that a screen appears where it says the brand of motherboard you have (in this it will indicate with which key you can access the BIOS setup).
If you could not enter the configuration menu because you did not have time, nothing happens: restart your computer and try again.
Then, as soon as you can see that your computer is turning on, press "F2" on your keyboard to access the BIOS.
It is important to know that not all BIOSes can be accessed by the "F2" key; some are accessed by keys such as “Del” or “Del”.
Once inside the BIOS setup menu, look for the following: "Exit." To get here you need to move in the menu using the Up - Right - Right - Right - Right keys.
Once in the submenu you will find several options, but you will choose the one that says: “Load Setup Defaults” (in Spanish it is “Load the default settings”). Then press ENTER to make the changes.
You need one more step. Go to the option “Exit Saving Changes” (in Spanish: «Exit saving the changes made») and press ENTER. Then a confirmation box will appear in which you will select “Yes” (in Spanish “Sí”), and press ENTER.
Once you have finished these steps, remove all the USB devices that you have placed in the computer (pendrives, USB type adapters, CD / DVD).
Ready! Now your computer must have restarted, and if it was a problem caused by somehow manipulating which hard drive started first in the BIOS, with the default configuration you should have solved it.
Other causes
What if the problem was not because it was changed which device will boot first? At this point we can tell you that you have run out of operating system.
You have lost the information you had inside the computer and what you have left is to reinstall the Windows operating system from scratch.
Reinstall the operating system
The first thing you should do is look for your Windows Live-CD of your choice. Turn on your computer, insert the CD / DVD, and then restart the computer so it can read it.
If your computer does not detect the CD / DVD, you must select boot. How? Restart the computer, and as soon as you see that the screen emits any image, press the F12 key; then select where you want your computer to start.
The Live-CD will start. Then choose the language in which Windows will be installed and click "Next".
Then the following dialog box will appear. Click "Install Now."
In the next step you will have two options: one is to update the system (but since we do not have a system, you must select the second one), and the other is "Custom". Click on that one.
Now you will see the units that your computer has. Select one of these and click "Next."
As you can see, the installation of your Windows has already started (you have to be patient and wait for the installation to finish).
Finally! You already have Windows installed again. Now you just have to customize it to your liking.
References
- Antoni F. Microsoft Team (2016). Error: Missing operating system. When I turn on my computer. Retrieved from: answers.microsoft.com
- Akheel Ahmed, Microsoft team (2016). After updates Windows 10 says «Missing operating system. Retrieved from: answers.microsoft.com.
- Ronny Vernon, Microsoft Team (2015). No operating system. Viewed at: answers.microsoft.com.
- Nikko Garcia, Microsoft Technical Team (2017). NMessage "No Operating System found". Retrieved from: answers.microsoft.com.
- Oracle (2010). Windows operating system installation guide. Recovered from docs.oracle.com
- Microsoft Team (2018). Specifications and system requirements for Windows. Consulted of microsoft.com.