Windows – How to create *from 0* a bootable disk partition for windows 10

bootwindows

I just cloned a hard drive partition (of Windows 10) to a new hard drive.

The thing is that I did it wrong and I just copied the data part, NOT the boot part. So now I have a new hard drive with a Windows copy with no boot partition.

I tested many tutorials, but the problem is that the bootable part NEVER existed on the new hard drive (so it can't be recovered!).

If someone knows how to create from scratch a new bootable partition for Windows 10. I have many licensed programs and lots and lots of configuration.

And if someone asks I just deleted all the data from the old hard drive (genius!), so I can't copy now the bootable disk partition.

Best Answer

There are general steps in the BCDBoot docs: https://docs.microsoft.com/en-us/windows-hardware/manufacture/desktop/bcdboot-command-line-options-techref-di#repair-the-system-partition

For UEFI the partition layout is documented at: https://docs.microsoft.com/en-us/windows-hardware/manufacture/desktop/configure-uefigpt-based-hard-drive-partitions

  1. Create a new "system" partition of approximately 250 MB:

    DISKPART> create partition efi size=250

  2. Format using FAT32, and assign a temporary drive letter:

    DISKPART> format quick fs=fat32 label="System"
DISKPART> assign letter="S"

  3. Install the files needed by Windows boot manager, together with an UEFI NVRAM "boot entry":

    C:\> bcdboot C:\Windows /s S:

For BIOS the partition layout is documented at: https://docs.microsoft.com/en-us/windows-hardware/manufacture/desktop/configure-biosmbr-based-hard-drive-partitions

  1. Create a new "system" partition of approximately 100 MB:

    DISKPART> create partition primary size=100

  2. Format using NTFS, and assign a temporary drive letter:

    DISKPART> format quick fs=ntfs label="System"
DISKPART> assign letter="S"

  3. Set the 'active' or 'bootable' flag for this partition:

    DISKPART> active

  4. Install a partition boot sector:

    C:\> bootsect S: /nt60

  5. Install a compatible MBR boot sector to the whole disk:

    C:\> bootsect S: /nt60 /mbr

  6. Install the files needed by Windows boot manager:

    C:\> bcdboot C:\Windows /s S:
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