When and who found an operating system

There are 5 perfect solutions to "Operating system not found" [MiniTool]

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Do you have the problem "No operating system was found“Affected when starting the PC? Do not worry! You can find the possible causes and 5 perfect solutions to this problem in this post. Now let's start.

Brief introduction to "No operating system was found"

While you are trying to start a Windows operating system, you may receive the error message "No operating system was found" displayed on the black screen. This is such an annoying mistake because it prevents you from booting into Windows. Well, what is the cause of this error and how can we "missing system" (missing operating system) get back? The answers are shown one by one throughout this article. Please read on.

5 causes that lead to the "Operating system not found" error

In general, both hardware problems and software failures can cause an operating system not to be found, and the following 5 are mainly listed here:

  1. The basic input / output system (BIOS) does not recognize the hard drive on which Windows will be installed.
  2. The hard drive has either physical or logical problems.
  3. User made wrong or unsuitable BIOS settings.
  4. The Windows Master Boot Record (MBR) on the hard disk is damaged or destroyed.
  5. The partition that stores Windows startup files is no longer active, or users set the wrong partition as active.

If one or more of these 5 problems happens, users get the annoying error message "Missing operating system“(missing operating system) or "Operating system not found". Fortunately, we have a solution for every cause. Let's see details.

5 solutions that can help you fix the missing operating system error

Since multiple problems can lead to the failure, most of the users do not know how to start the repair. Actually, they should better start by checking the hard drive for hardware failures and then finish checking software problems because the latter should be done based on the correct hardware condition. And the following 5 solutions are introduced in corresponding order.

Solution 1. Verify that the hard drive is recognized by the BIOS

If the system disk is not recognized by the BIOS, it cannot be used for reading and writing data. As a result, all files stored on the hard drive including the Windows operating system are inaccessible. If you dusted off or your computer took a severe shock before displaying the "Operating system not found" error, you will need to check to see if the hard drive was recognized by the BIOS. Detailed steps are as follows:

Start the computer and press a specific key to enter the BIOS. Usually it's F2, F10, Del, etc. However, different computers or motherboards require different keys, so you better search the internet or contact your computer manufacturer for the correct key.

In the BIOS you will find these or similar elements: IDE Primary Master, IDE Primary Slave, IDE Secondary Master, etc.

Please note:

If no disk is shown or the system disk is not here (it is shown as "None"Or"Not Detected"Displayed), we can say that the BIOS does not recognize the drive. At this point, different users should take different actions.

If you are able to remove the hard drive and then insert it correctly, please exit the BIOS and turn off the computer. Then disassemble the computer and reconnect the hard drive firmly. Assume that the "Missing Operating System" error (missing operating system) is displayed due to an unstable connection. The hard drive will reappear in the BIOS after reconnecting, and Windows may be bootable.

Tip: If you are unsure of the internal structure of the computer, think twice about whether you can do this job, because a small mistake can cause greater damage. And you'd better ask professionals for help.

But sometimes the target disk is still invisible even after we reconnected, and there are two possible reasons: the interface for the drive is prohibited, or the disk has been seriously damaged.

To deal with such situations, please highlight the option for the hard drive and press Enter. Then select “Auto” if there is such an option. If the hard drive is also not visible in the BIOS after we select "Auto", there may be serious problems and you should send it in for repair or replacement.

Even if the hard drive was recognized by the BIOS, we might get two different results: Windows starts successfully or Windows cannot start yet. If you unfortunately get the second result, please follow Solution 2 to check hard drive if there are any errors on the hard drive.

Solution 2. Check the hard drive whether it failed or not

Tip: If you are concerned about losing important files while checking the hard disk drive, you can transfer these files in advance. MiniTool Power Data Recovery Bootable Edition is one such bootable data recovery solution that can recover data without loading Windows and it can help you transfer data from an existing partition. For more information, see Power Data Recovery Boot Media.

Hard drive diagnostic tools are added on some types of motherboards to help users check the hard drive for errors, and you can enter the BIOS and see if there is such a tool on your motherboard. How to open BIOS we said in Solution 1.

I have an HP laptop that has such a utility:

Primary Hard Disk Self Test under Diagnostics is the tool that I can use to do a review. If you don't know how to use your diagnostic tool, check your computer or motherboard manufacturer's website for specific operations.

If a verification fails, users can contact their hard drive or computer manufacturers for a replacement, provided those devices are under warranty. However, to avoid data loss and privacy leaks, if their hard drives are still functional, users must perform the following two operations before replacing: Transfer all important and private data to create a backup. Delete the source data to avoid a data leak.

You can perform these operations on another computer as long as you have another regular computer available and know how to connect the failed drive as a second drive to the regular computer. Then just back up the data you want and clean the source disk. However, if a normal computer is not available, the best way to perform these operations is to use a bootable partition manager to copy the data you need, and then delete the source data. MiniTool Partition Wizard Bootable CD (embedded in paid editions of Partition Wizard) can support these processes.

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Before you start:

Steps to copy the hard drive or partition:

To copy a partition, select the target partition and select the option "Copy partition". To copy a data carrier, select the target data carrier and choose "Copy disk". Then follow the wizard to complete all the preparatory tasks. Finally click on "Take“To execute all changes.

Steps to clean up the hard drive or partition:

To delete a partition, select the target partition and select the option "Delete partition". To delete a data carrier, select the target data carrier and choose "Clean up disk". Then select a method to delete and click on "OK". Finally click on "Take“To execute all changes.

However, if all checks are passed, it is possible that the "Missing Operating System" error (missing operating system) is caused by software glitch and users can try the third solution.

Solution 3. Reset the BIOS to its default state

Sometimes incorrect or inappropriate BIOS settings can result in the operating system not being found. No error is found while checking hard drive, try resetting BIOS to default state and it may solve your problem. Detailed steps are as follows:

Restart the computer and enter the BIOS.

Find and enable the Standard Setup option, e.g. B. Load Optimal Defaults, Get Default Values, Load Optimized Defaults, Load Setup Defaults, etc.

Press F10 to save changes, and then exit BIOS.

However, if Method 3 doesn't solve your problem, your hard drive's MBR may have been corrupted.

Solution 4. Re-create the Master Boot Record

Both improper operation and a virus attack can cause MBR to become corrupt. As soon as this special start code (in the first sector of a hard drive) is damaged, Windows will not start. Well how can we repair or remodel MBR without loading the system? Users can turn to these three tools: Windows Installation CD / DVD, Windows Repair Disk, and MiniTool Partition Wizard Bootable CD.

Rebuild MBR using Windows installation disk or Windows repair disk

If you use the Windows installation diskette, start the computer with it, you will then be taken to the interface for selecting the language. Choose the settings you want and then click Next to continue.

Then select "Computer repair options". Then choose a system to repair and click "Next" for several recovery tools:

Here we can either "Startup Repair"Or"command promptSelect “to restore. However, because the first one automatically fixes any problems preventing Windows from starting, it will take a lot more time. So here we choose Command Prompt to open a Command Prompt window.

In the window we can "bootrec / fixmbr"Enter to repair MBR, and we can also"bootrec / fixboot" and "bootrec / rebuildbcdEnter “to carry out further repairs. Lastly, safely close the command prompt by typing exit.

Tip: Since the steps to fix MBR using Windows repair disks are very similar to the steps above, we are not introducing this program here.

After these operations, you can restart your computer to see if the "no operating system was found" problem has been resolved. Still, Microsoft says that the fixmbr command could corrupt the partition table if there is a virus or a hardware problem. Once the partition table is damaged, existing partitions become inaccessible, so data cannot be used. Is there a safer method? In fact, MiniTool Partition Wizard Bootable CD can help rebuild MBR without damaging data and partitions as only the master boot record is operated. For detailed steps, see Rebuilding the MBR.

Look here! I got the operating system back effectively.

However, if MBR repair still doesn't work, users need to try our last solution.

Solution 5. Activate the correct partition

When we run Windows under Legacy BIOS + MBR mode, the partition that stores boot files should be activated so that MBR can pass the boot privilege to the boot manager that Windows will find. For more information about activating the partition, see Accidentally Setting Drive C Active. If the wrong partition is activated, the operating system cannot be found. Fortunately, users can start their computer through a bootable partitioning tool and then see if the active partition is set correctly. If not, you can set the wrong partition as inactive and activate the correct partition. MiniTool Partition Wizard Bootable CD (embedded in the paid editions) can support these operations. Detailed steps are as follows:

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First, start the computer with MiniTool Partition Wizard Bootable CD, and then MiniTool Partition Wizard main window will appear.

Then check that the correct partition is activated. If there is no active partition or a wrong partition is marked as active, please click on the correct partition and select "Asmark active“.

Finally click on "Take“To make any changes.

For detailed steps, see Set Partition Active / Inactive. When all changes are complete, start Windows from the local hard drive.

Now all of the solutions to “Missing Operating System” or “Operating System Not Found” have been presented and you can try using these solutions if you have such question. If one or more of these solutions turns out to be useful to you, please share this post with others who have encountered similar issues.

“These 5 solutions to 'OS missing' and 'OS not found' have been found useful, and I find they will also be helpful for your friends who are suffering from this problem.” Click to tweet

However, if all of these solutions do not fit your situation, the problem could be very serious and you may need to reinstall Windows or contact your computer manufacturer or hard drive manufacturer for further assistance.

Tip: If you are planning to reinstall Windows but are afraid of losing desktop files as well as data stored in user documents, then you should use the Power Data Recovery Bootable Edition mentioned in Solution 2 to transfer the necessary data before reinstallation.
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PennyFollow us

Position: Columnist

She joined the MiniTool family in 2018. After that, she focuses on data recovery and disk management. Over the two years she has written many good posts and helped users get out of their data recovery and computer management problems.

In addition to knowledge of computer tricks, she is also interested in foreign languages, especially Japanese and Korean. She also likes animated films and feature films very much. “Good morning ... Oh, and if we don't see each other, good afternoon, good evening and good night!” Is her favorite movie quote.