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Deploy to UEFI-based Computers

The following topics describe the additional requirements for deploying Microsoft Windows to Unified Extensible Firmware Interface (UEFI)-based computers. There are two ways you can install Windows to UEFI-based computers:

  • Use Windows Setup
    By using Windows Setup, you can perform both attended and unattended installations of Windows. If you perform an unattended installation of Windows to a UEFI-based computer, your answer file must create additional partitions for the UEFI System Partition (ESP) as well as the Microsoft Reserved Partition (MSR).
    During attended installations, the ESP and BCD entries are automatically created and configured.
    Microsoft recommends that you use Windows Setup to install to UEFI-based computers. The process is simpler and less prone to errors.
  • Use ImageX
    By using ImageX, you can apply a Windows image to a UEFI-based computer. However, because UEFI-based computers require a separate ESP, you must also capture the ESP from the master computer and apply it to the destination computer. In addition, you must export the BCD store from the master computer and re-import the store on the destination computer. The partition structure of the master computer and destination computer must also match in partition sizes and types.

If you are new to UEFI-based computers, it is recommended that you perform an attended installation of Windows to the UEFI-based computer first. After Windows is installed, review the partition structure and BCD entries of the computer. This ensures that you are familiar with the requirements and configurations of UEFI-based computers.

Partition Configuration for EFI-based computers

For UEFI-based computers, each bootable drive must contain a Unified Extensible Firmware Interface System Partition (ESP), and at least one partition that contains an operating system. In addition, Microsoft strongly recommends that all GUID-Partition Table (GPT) disks include a Microsoft Reserved Partition (MSR). This partition is used by Windows to store metadata outside of the Windows volume. The MSR partition must exist between the ESP and the Windows operating system partitions.

If you perform an attended Windows Setup installation, The ESP and BCD entries are automatically created and configured during installation. If you perform an unattended Windows installation, you must create partitions for the ESP, MSR, and the Windows partition in your answer file.

The following table describes an example partition layout of a UEFI-based computer.


Partition Size Type Format

EFI System Partition (ESP)

200 megabytes (MB)




Microsoft Reserved Partition (MSR)

128 MB



Windows operating system partition

Available disk size



Other partitions, such as WindowsRE and Bitlocker partitions can be created after the MSR partition, but before the Windows operating system partition.

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