Cannot boot WinPE after installing it to a hard disk on a UEFI computer

Applies to: Windows 7 EnterpriseWindows 7 ProfessionalWindows 7 Ultimate

Symptoms


Consider the following scenario:
  • You have a computer which uses a Unified Extensible Firmware Interface (UEFI).
  • You are attempting to install Windows Preinstallation Environment (WinPE) to the hard disk, according to the instructions on Microsoft TechNet.
  • Or, you are attempting to deploy a Windows 7 or Windows Server 2008 R2 image to the hard disk using ImageX, according to the instructions on Microsoft TechNet.

In this scenario, the computer may fail to boot to WinPE, Windows 7, or Windows Server 2008 R2, even though you have confirmed that the EFI System Partition exists and an EFI boot loader program (\EFI\BOOT\BOOTX64.EFI) is present on it.

Cause


Because Windows Setup has not been run on this computer, there is no entry in the boot firmware NVRAM specifying a path to the EFI boot loader program. In this case, UEFI firmware is required to fall back to the default boot loader located at \EFI\BOOT\BOOTX64.EFI on the system partition. However, certain systems have been observed which do not adhere to this specification.

Resolution


Contact your hardware vendor to see if there is a firmware update available to resolve this issue.

You may also be able to work around the issue by either of the following methods:

  • Enter your computer’s BIOS setup and manually add a boot option to the firmware, pointing to “\EFI\Boot\Bootx64.efi” or “\EFI\Microsoft\Boot\Bootmgfw.efi” on the EFI system partition.
  • Or, run a full setup of the Windows operating system on the computer. During the setup process, Windows will add the appropriate boot entries to the system NVRAM.