Bare metal reset/recovery: enable your users to create recovery media

Recovery media (bare metal recovery) helps restore a Windows device to the factory state, even if the user needs to replace the hard drive or completely wipe the drive clean.

Windows uses the built-in Windows files, including recent Windows and driver updates, plus any customizations included in the OEM provisioning package, to create the recovery media.

If you deploy Windows using the default partition layout, your users will be able to create bare metal recovery media by default.

If you're deploying Windows with a custom partition layout, you'll need to add a few configuration files to enable your users to create bare metal recovery media:

• A partition reset script, which is a modified DiskPart script that resets your custom partition layout.
• A push-button reset configuration file (ResetConfig XML) that identifies the Windows and Windows RE partitions.

Creating configuration files

Partition reset script

1. In Notepad, create a configuration file that partitions the hard drive after the hard drive has been reset. This script should be the same as the script used to create partitions on the hard drive, with the following exceptions:

   • The script should not contain commands to select or clean the drive. Windows identifies the system drive automatically. To learn more, see Identifying the System Drive later in this topic.

   • The script should assign letters to the system partition, the Windows partition, and the Windows RE tools partition.

Examples:

UEFI (based on UEFI/GPT-based hard drive partitions):

rem == ResetPartitions-UEFI.txt ==
rem == These commands are used with DiskPart to
rem    reset the drive and recreate five partitions
rem    for a UEFI/GPT-based computer.
rem    Adjust the partition sizes to fill the drive
rem    as necessary. ==
rem == The differences between this file and
rem    CreatePartitions-UEFI.txt
rem    are noted in parenthesis.
rem       (NOT USED: select disk 0)
rem       (NOT USED: clean)
convert gpt
rem == 1. System partition =========================
create partition efi size=100
rem    ** NOTE: For Advanced Format 4Kn drives,
rem               change this value to size = 260 **
format quick fs=fat32 label="System"
assign letter="S"
rem == 2. Microsoft Reserved (MSR) partition =======
create partition msr size=128
rem == 3. Windows partition ========================
rem ==    a. Create the Windows partition ==========
create partition primary
rem ==    b. Create space for the recovery tools ===
shrink minimum=500
rem       ** Update this size to match the size of
rem          the recovery tools (winre.wim)
rem          plus some free space.
rem
rem ==    c. Prepare the Windows partition =========
format quick fs=ntfs label="Windows"
assign letter="W"
rem === 4. Recovery tools partition ================
create partition primary
format quick fs=ntfs label="Recovery tools"
assign letter="R"
set id="de94bba4-06d1-4d40-a16a-bfd50179d6ac"
gpt attributes=0x8000000000000001
list volume

BIOS (based on BIOS/MBR-based hard drive partitions):

rem == ResetPartitions-BIOS.txt ==
rem == These commands are used with DiskPart to
rem    reset the drive and create three partitions
rem    for a BIOS/MBR-based computer.
rem    Adjust the partition sizes to fill the drive
rem    as necessary. ==
rem == The differences between this file and
rem    CreatePartitions-BIOS.txt
rem    are noted in parenthesis.
rem       (NOT USED: select disk 0 )
rem       (NOT USED: clean )
rem == 1. System partition ======================
create partition primary size=100
format quick fs=ntfs label="System"
assign letter="S"
active
rem == 2. Windows partition =====================
rem ==    a. Create the Windows partition =======
create partition primary
rem ==    b. Create space for the recovery tools  
shrink minimum=500
rem       ** Update this size to match the size of
rem          the recovery tools (winre.wim)
rem          plus some free space.
rem ==    c. Prepare the Windows partition ======
format quick fs=ntfs label="Windows"
assign letter="W"
rem == 3. Recovery tools partition ==============
create partition primary
format quick fs=ntfs label="Recovery"
assign letter="R"
set id=27
list volume

2. Save your file, for example, E:\Recovery\RecoveryImage\ResetPartitions-UEFI.txt.

Push-button reset configuration file (ResetConfig.xml)

1. In Notepad, create a configuration file that points to your push-button reset partition script.

   For information about configuring this file, see ResetConfig XML Reference.

UEFI:

    <?xml version="1.0" encoding="utf-8"?>
    <!-- ResetConfig.xml for UEFI -->
    <Reset>
        <!-- May be combined with custom scripts – insert Run Phase elements here -->
        <SystemDisk>
            <DiskpartScriptPath>ResetPartitions-UEFI.txt</DiskpartScriptPath>
            <MinSize>75000</MinSize>
            <WindowsREPartition>4</WindowsREPartition>
            <WindowsREPath>Recovery\WindowsRE</WindowsREPath>
            <OSPartition>3</OSPartition>
        </SystemDisk>
    </Reset>

BIOS:

    <?xml version="1.0" encoding="utf-8"?>
    <!-- ResetConfig.xml for BIOS -->
    <Reset>
        <!-- May be combined with custom scripts – insert Run Phase elements here -->
        <SystemDisk>
            <DiskpartScriptPath>ResetPartitions-BIOS.txt</DiskpartScriptPath>
            <MinSize>75000</MinSize>
            <WindowsREPartition>3</WindowsREPartition>
            <WindowsREPath>Recovery\WindowsRE</WindowsREPath>
            <OSPartition>2</OSPartition>
        </SystemDisk>
    </Reset>

2. Save the file using the UTF-8 file format:

   Click File, and then click Save As. In the Encoding box, select UTF-8, and save this file as E:\Recovery\RecoveryImage\ResetConfig.xml.

Enable users to create media

Users can use this option to create recovery media when needed.

Step 1: Add the configuration files to the destination computer

1. On your destination computer, insert the USB flash drive with the configuration files.

2. Copy the configuration files to the destination computer:

    Copy E:\Recovery\RecoveryImage\* R:\RecoveryImage\*

where E is the drive letter of the USB flash drive and R is the drive letter of the recovery image partition.

Step 2: Test that Windows can create recovery media

1. Restart the destination computer, and complete Out-Of-Box Experience (OOBE).

2. Click Start, type create a recovery drive, and select Create a recovery drive, and click Yes at the UAC prompt.

3. Insert a USB flash drive.

4. Select Copy the recovery partition from the PC to the recovery drive > Next > Next > Create.

Step 3: Test the recovery media

1. On a computer that has no operating system, insert your recovery media.
2. Start the computer, press a key to open the firmware boot menus, and then select the appropriate boot device.
3. At the Windows RE Tools menus, select a keyboard layout, for example, US.
4. Click Troubleshoot > Remove everything > Next. If you're prompted to clean the drive, select Yes.
5. Select Yes, repartition the drives > Just remove my files > Reset.

Troubleshooting

• Make sure that ResetConfig.xml is saved as a UTF-8 file.
• Make sure that the filename listed in the <DiskpartScriptPath> element of the ResetConfig.xml file matches the filename in the Diskpart script.
• Make sure that the Diskpart script doesn't include commands to select the drive or clean the drive (select disk 0, clean).

Identifying the system drive

Windows identifies the system drive using the following methods:

BIOS-based computers: the BIOS-reported system drive is used.

UEFI-based computers: When Windows RE is enabled by using the reagentc /setreimage command, Windows writes the adaptor location path and GUID of the system disk to a UEFI variable. This step is only performed when both the system and OS partitions are on the system drive. The variable is updated if necessary when Windows RE gets disabled and then re-enabled.

If multiple local drives are detected, Windows identifies the system drive by searching in the following order

1. Windows searches for a drive with a GUID matching the value stored in firmware.

2. Windows searches for a drive with a location path matching the value stored in firmware.

3. Windows searches for a drive with an existing ESP.

   If multiple drives with ESP are found, the recovery process will not proceed.

4. Windows searches for an uninitialized (raw) disk.

   If multiple uninitialized disks are found, the recovery process will not proceed.

Related topics

Push-Button Reset Overview

ResetConfig XML Reference

Bare metal reset/recovery: create recovery media while deploying new devices

UEFI/GPT-based hard drive partitions

BIOS/MBR-based hard drive partitions