Saturday, 29 September 2012

Steps to deploy Windows 8 OS(x64) using UEFI Boot

Steps to deploy Windows 8 OS(x64) using UEFI Boot

1)     Upgrade to latest BIOS. Before you install in UEFI mode you should generally check with the vendor to make sure the BIOS is up to date

2)     Configure the computer for UEFI. Most UEFI based computers will also support legacy BIOS boot. This is configured in the BIOS. The following shows the computer is set for Legacy Boot and the boot options available with Legacy Boot


3)      Insert Windows 8 RP/RTM (x64) DVD.

 Note: One of the common issues we see is that users try to install x86 or 32 bit version with UEFI enabled in the bios. x86 does not support UEFI so you would have to configure the machine for Legacy boot to install x86 versions of Windows. If you do try to install x86 version setup will run but on the 1st reboot you will get BIOS error similar to “No bootable devices –Strike F1 to retry boot, F2 for setup utility. Press F5 to run onboard diagnostics”

4)     Press F12 to choose to boot from the DVD and choose the UEFI boot option for the DVD

Note: The UEFI option for the DVD under UEFI boot

5)     Follow prompts to install Windows 8 just like any other install

NOTE: Make sure the Hard disk you would put your installation on is fully blank without any partitions 

·         In case there are some partitions already present, format and delete all the partitions. Now the Hard disk should have an Unallocated space as shown below

 ·         Once you click "New", you will notice it created 3 partitions compared to the usual two. That is because Windows has automatically formatted the Disk to GPT, not MBR

Unlike MBR (the "normal" disk), GPT requries 3 partitions. The 3 partitions are:

  • Partition 1 - ESP

-The ESP contains the NTLDR, HAL, Boot.txt, and other files that are needed to boot the system, such as drivers

  • Partition 2 - MSR

-Microsoft Reserved Partition (MSR) reserves space on each disk drive for subsequent use by operating system software.

  • Partition 3 - Operating System

-Your data and everything else

You cannot see the second partition in Windows except for DISKPART. You can see the first partition in Disk Management. It is imperative that these 3 partitions remain in the exact order as they are

Select Partition 3 for your OS installation

Warning: Disabling UEFI will make the system unbootable as there is no MBR on the disks

Differences between UEFI vs. Legacy BIOS boot install

When complete you will find couple of differences compared to a legacy BIOS boot.

You have the following default disk configuration:

·         100MB Fat32 EFI System Partition

·         128MB Microsoft Reserved Partition (will not appear in Disk Management but you can see it in the command line Diskpart tool)

More information on the default partitioning for UEFI based computer can be found at

6)     In the properties of the disk you also see that we setup a GUID Partiiton Table (GPT) instead of MBR:


·         MBR is the standard partitioning scheme that's been used on hard disks since the PC first came out. It supports 4 primary partitions per hard drive, and a maximum partition size of 2TB.

·         GPT disks are new, and are readable only by Windows Server 2003 SP1, Windows Vista (all versions), and Windows XP x64 Edition. The GPT disk itself can support a volume up to 2^64 blocks in length. (For 512-byte blocks, this is 9.44 ZB - Zettabytes. 1 ZB is 1 billion terabytes). It can support upto 128 possible partitions


7)     On Dell E6x20 series  you can see in the BIOS settings that Windows 8 setup added a new boot option

 Boot Option Name: Windows boot Manager
File Name: \EFI\Microsoft\Boot\bootmgfw.efi
8)     If you are doing a large deployment to many machines not all deployment tools support UEFI yet so check with the vendor of the deployment tool to see if they support UEFI based computers.
Information on Microsoft deployment tools support for UEFI can be found at

1 comment:

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