Error Operating System not found: what to do?

Probably, there is no need to explain how uncomfortable is the situation when a user turns on a computer or laptop for downloading and instead of the usual start the system writes the Operating System not found on the screen. For many users this causes a real shock. How so? Yesterday everything worked ... What could happen, and how to fix this situation, we now look.

What is the error of Operating System not found?

If you look at the message itself, it's easy to translate it as "the operating system is not found." But the trouble is that the user is absolutely sure that it is there. But the computer system does not share such confidence with the user, because it simply does not find the components responsible for the system load.

In general, such situations are most often manifested, for example, when a user took a winchester, replaced it with a new one. Maybe it's just that the hard drive was out of order, but it's not enough.

Possible causes of

If this happens, and the system constantly displays the message Operating System not found (Windows 7, 8, etc.), first of all, do not panic. To begin with, just check, maybe a flash drive is inserted into the computer or laptop, and in the BIOS settings, the USB device is the priority for downloading.

If the hard drive was removed or changed to a new one (this applies to stationary computers), it may very well be that when the connection was reconnected, the corresponding loops were incorrectly or loosely connected. Let's see what can be done in this situation.

Basic BIOS settings

The easiest way to change BIOS settings is to reset all settings to the factory default settings. In any version of the BIOS there is such a setting.

In extreme cases, you can simply change the boot priority in the Boot Device Priority or Boot Sequence section, and install the hard drive as the first (main) boot device (boot device).

It happens, however, and such that the hard disk in the BIOS is determined, but the download still does not occur, and the system again and again issues an alert Operating System not found. What to do in this situation? First, see if the exclamation point is not opposite the hard drive model . It signals that the device in the system, although present, is simply disabled or not involved.

As a rule, in most versions of the BIOS on the right, there is a special help field for the device (Specific Item Help), which specifies a shortcut that allows you to enable or disable any component. The most likely combination is Shift + 1. But here everything depends on the manufacturer (the combinations can be different).

Switching the modes of the hard drive in the UEFI BIOS

On the other hand, if there is an alert Operating System not found on the laptop, where to remove the hard drive is quite problematic, it is worth paying attention to the settings of the operating modes of the hard disk. As an example, consider the settings of the newest UEFI system, although they can be used without problems in other versions.

In general, there are two main modes in the SATA configuration: AHCI and IDE. At the initial installation of "OSes", as well as in the default settings, AHCI mode is enabled. When you switch to the IDE, no matter how hard you try, you can not install Windows on the hard drive.

The same applies to the moments when users at the end of the installation process, whether by ignorance, or accidentally include exactly the IDE mode. As you can see, the system displays the Operating System not found line. By the way, even if at the moment to put another fully operational "screw", without changing the SATA settings to the initial ones, it will not work either.

Therefore, once you should advise users to change these settings only in the most extreme case, when this is really necessary.

Restoring the Windows boot loader

Frequently, there are cases when the message "Operating System not found" appears when the Windows boot loader is damaged, which is due only to errors on the hard disk, for example, due to incorrect shutdown. At the same time, as it is already clear, the whole system can "fly off".

In this situation, you can try to restore the bootloader, and at the same time and check the system drive or partition for any errors. To do this, it is always at hand to have an original installation disk or a system disk for recovery.

Here you need to set the optical drive in the BIOS as the first priority device to boot, then use the Recovery Console. Note, in this case, there is no question of restoring Windows from a control point. This still does not help, and the Operating System not found warning will appear again.

Here you need to use the boot recovery mode or the command line, which is preferable. It consistently needs to enter two basic commands: bootrec.exe / FixMbr and bootrec.exe / FixBoot, after each pressing "Enter". If such a sequence does not help, you can also add the bootrec.exe / RebuildBcd command.

Before performing such actions, it is highly recommended to check the disk for errors with their automatic correction (chkdsk / f / r or chkdsk / f / x / r commands). You can also use the chkntfs / xc checker: if there is an NTFS file system in the system partition (drive "C").

If nothing has helped

However, if all the above-mentioned methods of fixing the situation do not help, then certainly it is necessary to diagnose the hard disk. That's only if for stationary computers to remove it is not a problem, then the laptop will have to contact the nearest service center or workshop and not try to remove it yourself.

As it is already clear, if the hard drive "poured", that can not be helped, it will have to be changed to a new "hardware", after which you will install the "operating system" again. You can, of course, try the HDD Regenerator utility on it , but 100% success in recovering the hard disk is difficult to guarantee.