The "Operating system not found" error can be solved through the following steps: 1. Check whether the hard disk connection is normal, ensure that the data cable and power cable are tightly inserted, and replace the cable or interface if necessary; 2. Enter the BIOS to confirm that the hard disk is recognized and set the boot sequence correctly, and adjust the Secure Boot status; 3. Use the Windows installation USB flash drive to repair the boot record, and execute the bootrec /fixmb, bootrec /fixboot and bootrec /rebuildbcd commands in turn; 4. Check the hard disk partition table, view and repair the EFI system partition through the diskpart tool, ensure that the GPT is consistent with the MBR, and be careful when operating to prevent data deletion.

The "Operating system not found" error usually occurs when the computer starts, and the system cannot find valid operating system boot information. This problem may be caused by hardware, BIOS settings, or system files corruption. The following are some common reasons and corresponding solutions to help you troubleshoot and solve problems step by step.

1. Check whether the hard drive connection is normal

This is the easiest to be overlooked but the most basic step. If the hard disk data cable or power cable is loose, the motherboard will not recognize the hard disk, and the operating system will naturally not be found.

• Turn off the computer and unplug it
• Open the chassis and check whether the SATA or M.2 interface is tight
• If it is a laptop, you can try to remove the battery and plug it in the hard drive again (note the static electricity)

If it is a desktop computer, you can also try changing a SATA cable or changing a SATA interface on the motherboard.

2. Confirm that the hard disk is recognized in the BIOS

Sometimes the hard drive is fine, but the BIOS does not correctly recognize or set the startup sequence.

• Press Del/F2/F10 when booting (the specific buttons vary depending on the motherboard brand) to enter the BIOS
• Check if the hard disk is detected in the Main or Boot tab
• If you don't see the hard drive, it may be the connection problem mentioned above
• Enter the "Boot" menu and confirm that the first boot device is set to your system disk (such as Windows Boot Manager)

If you are using UEFI mode, it will help to make sure Secure Boot is on or off.

3. Repair the boot record (MBR/GPT)

If the hard disk exists but the system still reports an error, it is likely that the boot area is damaged. At this time, you can repair it by installing a USB drive on Windows.

Prepare a Windows installation USB drive, and then:

• Insert the USB drive and boot from the USB drive

• After you reach the installation interface, click "Repair Computer"

• Select "Troubleshoot → Advanced Options → Command Prompt"

• Enter the following three commands (click Enter for each input):

   bootrec /fixmbr
  bootrec /fixboot
  bootrec /rebuildbcd

These three steps are used to repair the main boot record, boot sector and rebuild BCD (boot configuration data). After completion, enter exit and restart to see if it is restored.

4. Check whether the hard disk partition table is normal

If the boot repair is invalid, it may be that the partition table of the hard disk is wrong, especially the inconsistency between GPT and MBR.

• Also use Windows to install the USB drive to enter the command prompt

• Enter diskpart

• Then enter:

   list disk
  select disk X (X is the hard disk number where your system is located)
  list partition

Check if there is an EFI system partition (ESP), if not, a manual reconstruction may be required. This situation is a little more complicated. It is recommended to have a certain understanding of disk operations before trying, otherwise it will be easy to delete data by mistake.

Basically these common inspection methods. In most cases, it can be done by checking the hardware connection, BIOS settings, and repairing the boot. When encountering problems, don’t rush to reinstall the system. Check it step by step first. In many cases, it is just a small failure.

The above is the detailed content of How to fix 'Operating system not found' error in Windows?. For more information, please follow other related articles on the PHP Chinese website!