Operating System not found error: what to do? Operating system not found: what is this error and how to deal with it Operating system not found on an acer laptop

One of the most terrible user errors is the one that appears when you turn on the computer and tells us, on the BIOS black screen, that "". When this message appears, our system will not be able to boot, and the only way out is to restart the computer by pressing "ctrl + alt + del", and in doing so, you will most likely see this message again.

The problem of the error is that the operating system is not displayed and therefore the BIOS cannot boot the Windows system. The reasons for this error to appear are very diverse, from a simple configuration error in the BIOS to a more serious problem that, in the worst case, forces us to completely format the computer. Therefore, we will analyze the main causes and their solutions to eliminate the error "" ( An operating system wasn't found).

Disconnecting external USB devices from the computer

If your computer has multiple internal hard drives, external drives, and USB sticks connected, it is likely that BIOS is trying to find the operating system in the wrong place. Therefore, not finding the Windows system, it gives the error "No operating system found".

• To solve this problem, you need to disconnect all external storage devices connected to the USB ports and try again. We can also check our optical drive to make sure it's not trying to load the wrong DVD.

If after doing this the problem is still not resolved, the next step is to go into the BIOS setup.

Changing BIOS Boot Priority

Enter the BIOS configuration by pressing the F2, F12 or Delete buttons. After that go to the configuration section Boot and put in the first place in the column priority a hard drive that contains the working and primary Windows operating system. In different BIOS versions, it is called differently, but you are looking for a word with a combination of Priority, which means "priority boot". Here are some names from different BIOSes: Hard Disk Priority, Boot Device Priority, Hard Disk Boot Priority.

After you have set the boot priority from the hard disk where your system is located, do not forget to save the settings with the F10 button and restart the computer to make sure "is the system found when you turn on the computer".

Enable or disable Secure Boot

If you are using a modern computer with an operating system such as Windows 8 or Windows 10, then perhaps the reason why our Windows does not start is in the wrong UEFI secure boot setup.

Go back to BIOS, find the configuration section secure boot(Secure Boot) and deactivate it, or activate it if it is disabled, to check if the error "Operating system not found when booting the computer" is gone.

In different versions of the BIOS or UEFI, the location of the settings looks different, but in any BIOS version, look for the column secure boot try turning it off or on.

Reset BIOS to factory settings

At the bottom of the BIOS menu you will see a key to default settings or BIOS reset. On my car it is F9. Confirm your decision when prompted and restart your computer.

If you did not find an approximate button, like F9 to reset the settings to factory settings, then look for the line Load Setup Default and reset BIOS.

If your operating system hard drive is placed first, but the computer still won't boot, it's possible that some of the initial sectors of the drive have been corrupted, such as master boot record(MBR) DOS boot record(DBR) , or Boot configuration database(BCD).

The repair of these sectors is quite simple. All we need is to create a Windows installation USB flash drive and through it enter the advanced boot options.

Enter the following commands in CMD in order by pressing enter. Each command may take time to complete.

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

Activate the Windows Partition

It is possible that the partition where Windows is installed is disabled. You can fix this using Windows' native diskpart tool. To complete the following steps, you will again need a USB flash drive to install Windows. Launch the command prompt as described above via the recovery disk or the Windows installation flash drive and type the following commands at the command prompt:

• diskpart- Launching the tool.
• list disk- List of connected disks to the computer.
• select disk 0- Select the hard disk on which you want to activate the partition. In my case, the primary hard drive is 0.
• list volume- Shows the partitions on the selected hard drive.
• select volume 2- Select a local drive to activate. Choose the one where the widows system itself is installed.
• active- Activate section.

Restart your computer and check if the error is gone when you turn on your computer An operating system wasn't found. Ttry disconnecting any drives that don't contain an operating system. Press Ctrl+Alt+Del to restart which means operating system not found, press ctrl+alt+del to reload.

Hello admin, an inscription appears on the monitor when the computer is booted Operating System not foun d, the error appeared after trying to overclock the computer's processor. I tried to find an answer on various forums on the Internet, basically they advise resetting the UEFI BIOS settings to default and booting from the "kolobok" and see if the operating system files are in place, they also advise to plug the information cable connecting the hard drive to the motherboard.
Gingerbread man, I don’t know what it is (this is a Live CD note by the administrator), but the cable didn’t just tuck, but even changed and tried to connect it to other SATA connectors on the motherboard, but it didn’t help. What else can be done?

Operating System not found

Hello, friends! Since I work in a regular service center, I often deal with this problem. And in this article I will just give real examples of the occurrence of this error and tell you how to deal with them. This error comes out Operating System not found(no operating system files found) or other (reboot and select correct boot device or insert bootable media) for reasons that can be divided into two parts. Basically, this error is associated with "iron" problems: the SATA information cable has gone, a faulty hard drive, incorrect BIOS settings, and even a faulty power supply. But this error can also appear due to various violations in the boot sector of the hard disk and the boot files of the Windows operating system itself.

Firstly, the Operating System not found error may appear due to the fact that, in the BIOS, the boot priority of the computer is incorrectly set, that is, the boot is set not from the hard disk on which the operating system is installed, but from a DVD-ROM or even from FDD (floppy -disk drive), remember the last actions you performed with your computer, maybe yesterday you changed the priority of the boot device in BIOS and booted your laptop from a USB flash drive, then forgot to set the boot from the hard disk, as a result, the next time you boot your computer or laptop, it may exit Operating System not found error. and set the boot priority from the hard drive. Secondly, pay attention to whether a USB flash drive is connected to your computer or laptop, it is quite possible that the computer wants to boot from it, but it is not bootable at all. Thirdly, maybe you recently disconnected your hard drive and went with it to your friends to exchange files, check with the computer turned off whether your hard drive is securely connected by a SATA information cable to the connector on the motherboard, if there is another SATA cable, try using it or just plug the hard drive into another SATA connector on the motherboard.

Fourth, immediately after installing the operating system, many users, without the appropriate knowledge, start experimenting with BIOS, who want to overclock the processor, and who just "study" the new UEFI BIOS, and who need to set the computer to boot from a disk or flash drive. As a result, users change the initial and workable BIOS settings very much, but not everyone knows how to return them to their original position.

A simple example related to our mistake: in almost any BIOS, including the most modern UEFI, there is an option responsible for the operation of the hard drive controller, in most cases it is called "SATA Configuration" or SATA Configuration, this option can be set to AHCI or IDE. So, AHCI is a modern technology for the operation of SATA II and SATA III hard drives and SSD SSDs. On all modern UEFI BIOSes, the SATA Configuration option is set to AHCI by default, and it turns out that when you install the Windows operating system on a new computer or laptop, AHCI is enabled. After installing the operating system, some users accidentally or intentionally turn off AHCI in the SATA Configuration settings and turn on the IDE, as a result, when the computer or laptop boots, a blue screen or an Operating System not found error occurs. To solve the problem, reset the UEFI BIOS settings to default and try to boot the operating system.

Sixth, your hard drive may simply be faulty. Note. Is your hard drive detected in BIOS. If not, then you need to look for the cause of this misunderstanding. In this case, pay attention to the solutions already described in paragraph 4 of this article, reset the BIOS to default settings, reconnect the SATA information cables or connect the hard drive to another connector on the motherboard, if this does not help, you can try connecting the hard drive to another computer and see if your hard drive is detected in the BIOS of another computer, if not, the hard drive is probably faulty, contact a service center to solve the problem.

Of course, I understand that it will be difficult for a simple user to remove a hard drive on a laptop, in this case you just need to limit yourself, if after that the hard drive is also not detected in the BIOS and the laptop will give an Operating System not found error when booting, do nothing more and contact the service center. If the hard drive is detected in the BIOS, then you should try to restore Windows boot (as written in paragraph No. 5), if nothing works, then you need to boot the laptop from any Live CD and copy all the important files from the hard drive to a portable USB hard drive, then .

Once in my practice, I had to deal with this error and imagine, the whole thing was decided by replacing the power supply. Due to a faulty power supply, the hard drive was no longer detected in the system and this Operating System not found error began to appear during boot, after replacing the power supply everything returned to normal, I described this and many more problems in the article.

Sometimes Windows Update fails and the operating system stops loading. This can also happen when more than one version of Windows is being installed on the same computer. We offer one of the options for solving the problem with loading the system.

To perform a computer recovery procedure, you will need a Windows installation CD or Recovery CD for Windows.

1. Insert the Windows disc into the drive
2. Restart PC
3. Enter BIOS
4. Change boot order - priority to boot from CD/DVD
5. Save and restart your computer
6. Select a language and then click "Next"
7. Click on the System Restore button
8. Select the operating system, most likely there will be only one system in the list, then click the "Next" button again
9. Select "Use recovery tools" that can help fix problems with Windows and click "Next"
10. Click "Start Repair"

Your computer will restart again. Take the disk and change the boot order in the BIOS back to the hard disk first. Windows should boot up.

At this point, try running Windows Updates again and see what is needed to install them. If the problem occurs again, try repeating the first 8 steps above. After selecting the operating system, click the Next button,

1. Click "Open Command Prompt".
2. Enter " FIXMBR" (in Windows XP) or " Bootrec.exe / FIXMBR" (in Windows 7).
3. Press Enter .

Restart your computer and check which of the recovery options worked.

Please note that if your operating system does not appear when choosing a system, then most likely your hard drive is faulty. There is only one way out - replacing the hard drive with a working HDD.

Users of the Windows operating system are already used to seeing error messages instead of the loading screen from time to time. The types of problems are different, but in any case they require urgent action. The operating system not found error can be found both on a laptop and on a desktop computer. The user sees this inscription on a black background, after which the system does not boot. Or rather, the computer reports its absence. Of course, this is not the case, and it is possible and necessary to fix the problem. Let's figure out what caused it and how to proceed.

Troubleshooting the Operating system not found error.

As already mentioned, the error “operating system not found” literally means “the operating system was not found”. There may be several reasons:

• Hard disk failure or incorrect cable connection;
• Incorrectly set BIOS parameters;
• Problems with the power supply or motherboard.

Let's consider each aspect in detail.

Error Correction Methods

What to do first of all when “operating system not found” appears? You can find out the reason in stages, checking all the components necessary for loading the OS in turn.

It is better to start with the most harmless - checking the settings. Most often, this error occurs in cases of incorrectly set hard disk priority. For example, a flash drive is inserted into a computer or laptop, and the BIOS has priority on USB drives. Also, the reason may be in an incorrectly connected cable, especially if you changed or reconnected the hard drive the day before.

To check the priority for loading, do the following:

• We go into the BIOS;
• Select the Boot tab (sometimes Advanced);
• We check where the HDD is located (should be in the first place);
• If necessary, rearrange it using F5, F6 or arrows, depending on the BIOS version.

ADVICE. If the settings are correct, try resetting the BIOS. New errors will not appear because of this, but this particular one may disappear. We will tell you how to do this below.

Reboot the system and check if it helped. If not, we move on.

Hard drive problems

In cases where the error “an operating system wasn’t found” is still displayed, or the BIOS does not see hard drives at all, then there may be two reasons:

1. Disconnected hard drive or cable;
2. The hard drive is defective.

In the first case, you need to completely turn off the PC and double-check all connections. In the second case, it remains only to connect the hard drive to another computer and see if the error occurs there.

ADVICE. The density of the elements in the laptop does not allow the cable to move away, so the probability of solving the problem on the laptop in this way is extremely small.

So, you checked everything, but the problem did not go away. Do not panic, there are a couple of other ways to solve the problem.

Reset BIOS settings and install fresh firmware

As we mentioned earlier, a factory reset can help. They are called Default and are available on all BIOS versions. There are times when the system sees the hard drive and detects it, but does not load it. The first thing to do is to check its status. If there is an exclamation mark next to the hard drive, then this indicates that the drive is disabled or not used. Enabling it is simple:

1. Choose a problematic hard drive;
2. Find the Specific Item Help field (this is the device help tab);
3. We look at what keyboard shortcuts you can turn on a particular device.

ADVICE. On different versions of the BIOS, the combinations are different, but most often it is the combination Shift + 1.

After that, the hard drive should turn on, and the computer should start without problems. If this does not happen, we try other methods.

A damaged Windows bootloader can also cause not only an error, but a complete system crash. You can try to restore it using the installation disc or the recovery disc.

1. Insert the source into the drive;
2. We start the BIOS and select the optical drive there as a priority device for booting;
3. Select the recovery console.
4. We are trying to restore the boot mode and check the disk for errors with the possibility of automatic recovery.
5. Alternatively, you can use the command line by typing bootrec.exe /FixMbr, and then bootrec.exe /FixBoot. Don't forget the Enter key after each line.

ADVICE. If your C drive has an NTFS file system, try using chkntfs /x c: as a check.

Having tried everything and not getting a result, be sure to diagnose your hard drive. In the case of a laptop, you will have to contact the workshop, as independent attempts to remove it can aggravate the situation. Try to use the HDD Regenerator utility to restore the hard drive, but the percentage of success is low. Well, a faulty hard drive must be replaced and reinstalled the entire operating system.

We hope you did not have to resort to the help of computer services and managed to fix the problem yourself. Ask your questions in the comments.

Probably, there is no need to explain how unflattering the situation is when a user turns on a computer or laptop to boot and instead of the usual start, the system writes Operating System not found on the screen for no reason at all. For many users, this is a real shock. How so? Yesterday, everything worked… What could have happened, and how to fix this situation, we'll see now.

What does the Operating System not found error mean?

If you look at the message itself, it's not hard to translate it as "operating system not found". But here's the problem - the user is absolutely sure that it exists. But the computer system does not share such confidence with the user, because it simply does not find the components responsible for loading the system.

In general, such situations most often appear, for example, when a user removes a hard drive and replaces it with a new one. Maybe just the hard drive is out of order, but you never know what.

Possible causes

If such an incident suddenly turned out, and the system constantly displays the message Operating System not found (Windows 7, 8, etc.), first of all, do not panic. To get started, just check if a flash drive is inserted into the computer or laptop, and in the BIOS settings, the USB device is the priority for booting.

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

Basic BIOS settings

The easiest way to change BIOS settings can be to reset all settings to the factory defaults (Default). Every BIOS version has this 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 also happens, however, that the hard drive is detected in the BIOS, but it still does not boot, and the system again and again gives the Operating System not found warning. What to do in such a situation? First, see if there is an exclamation mark next to the hard drive model. It signals that the device in the system, although it is 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 contains a keyboard shortcut that allows you to enable or disable any component. The most likely combination is Shift + 1. But here everything depends on the manufacturer (combinations may be different).

Switching hard drive operating modes in BIOS UEFI

On the other hand, if an Operating System not found warning appears on a laptop, where it is quite problematic to remove the hard drive, you should separately pay attention to the settings of the hard drive operating modes. As an example, consider the settings of the latest 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. During the initial installation of the OS, as well as in the default settings, AHCI mode is enabled. When you switch to the IDE, no matter how you try, you won't be able to install Windows on the hard drive.

The same applies to the moments when users, at the end of the installation process, either out of ignorance or accidentally turn on the IDE mode. As it is already clear, the system issues the line Operating System not found. By the way, even if you put another fully functional “screw” at the moment, it will also not work without changing the SATA settings to the initial ones.

Therefore, it is immediately worth advising users to change such settings only as a last resort, when it is really necessary.

Restoring the Windows bootloader

There are also frequent cases when the message “Operating System not found” appears when the Windows bootloader is damaged, which is associated only with errors on the hard disk, for example, due to incorrect shutdown. In this case, as is already clear, the entire system can “fly off”.

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

Here you will need to set the optical drive in the BIOS as the first boot priority device, and then use the recovery console. Note that in this option there is no question about restoring Windows from a checkpoint. This still won't help and the Operating System not found warning will reappear.

Here you need to use boot recovery mode or command line, which is preferable. In it, you need to sequentially enter two main commands: bootrec.exe /FixMbr and bootrec.exe /FixBoot, after each pressing "Enter". If such a sequence does not help, in addition, you can add the bootrec.exe /RebuildBcd command.

Before performing such actions, it is strongly recommended to check the disk for errors with their automatic correction (commands chkdsk / f / r or chkdsk / f / x / r). You can also use the chkntfs /x c: checker if you have an NTFS file system on your system partition (drive C).

If nothing helped

However, if all the above methods of correcting the situation do not help, then you should definitely diagnose the hard drive. But if it’s not a problem to remove it for stationary computers, then with a laptop you 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 “fell down”, there’s nothing to be done, you will have to change it to a new “hardware”, and then install the “OS” again. You can, of course, try the action of the HDD Regenerator utility on it, but it is quite difficult to guarantee one hundred percent success in restoring a hard drive.