Repair the boot menu on a dual-boot PC

  • บทความ

When setting up a PC to boot more than one operating system, you may sometimes lose the ability to boot into one of the operating systems. The BCDBoot option allows you to quickly add boot options for a Windows-based operating system.

Repairing a Windows partition on a dual-boot PC

  1. Start with a PC that has Windows installed on its hard drive.
  2. Install a separate hard drive or prepare a separate partition that you'll use for another Windows installation.
  3. Install the new operating system on the hard drive or partition you configured in the previous step. For example, if your PC has Windows 10, install Windows 11 onto the other hard drive or partition.
  4. Reboot the PC. The boot menus should appear with both operating systems listed.

If both operating systems aren't listed

If you've installed two versions of Windows on the same PC but they don't both appear in the boot menu when you start your PC, you can manually add a Windows installation:

  1. Open a command line and use Bcdboot to add the new operating system to the boot menu (see the note below about options for how to get to a command line):

    Bcdboot D:\Windows

    Where D:\Windows is the path to the new Windows installation. If you need to find the drive letter of your Windows installation, run diskpart and then list volume to see the letters assigned to your PC's drives.

    Note

    You can get to a command line using any of these methods:

    • Booting into Windows and opening Command prompt as administrator.
    • Boot the PC from Windows installation media and presssing Shift+F10.
    • Booting to Windows PE.

  2. Reboot the PC. Now, the boot menu will show both menu options.

BCDboot Command-Line Options