Hard Drives and Partitions Overview

Applies To: Windows 8, Windows 8.1, Windows Server 2012, Windows Server 2012 R2

This topic describes different hard drive and partition configurations that you might find when you deploy Windows® on different computers.

In this topic:

  • Drive Types

    • Solid-State Drives

    • Advanced format drives

    • Factory-Encrypted Hard Drives

    • Multiple Hard Drives

  • Partitions

    • System Partitions

    • Recovery Partitions

    • Data Partitions

Drive Types

You can install Windows to a hard drive, such as a hard disk drive or a solid-state drive. For additional security, you can use hard drives that the factory has pre-encrypted. A single computer may contain multiple drives.

Solid-State Drives

A solid-state drive (SSD) is a data storage device that uses solid-state memory to store persistent data. An SSD must have a minimum of 16 gigabytes (GB) of space to install Windows® 8. For more information about drive space and RAM considerations, see Solid State Drive Deployment.

Advanced format drives

You can use some Advanced Format Drives to provide additional drive space.

Advanced Format 512 emulation (512e) drives are supported on either BIOS-based or UEFI-based computers.

Advanced Format 4K Native (4Kn) drives are supported on UEFI-based computers only.


For Advanced Format 4K Native drives (4-KB-per-sector) drives, the minimum partition size is 260 MB, due to a limitation of the FAT32 file format. The minimum partition size of FAT32 drives is calculated as sector size (4KB) x 65527 = 256 MB. For more information, see Configure UEFI/GPT-Based Hard Drive Partitions.

Factory-Encrypted Hard Drives

To help protect your deployment environment, you can use a factory pre-encrypted hard drive to prevent unauthorized access before you install Windows or any other software. For more information, see Factory Encrypted Drives.

Multiple Hard Drives

If you install Windows on a computer that has multiple hard drives, you can use the disk location path to make sure that your images are applied to the intended drives.

To do this, use the diskpart SELECT DISK=<disk location path> command to select each drive. For example:



The system drive might not appear as disk 0 in the DiskPart tool. The system might assign different numbers to drives when you reboot. Different computers that have the same drive configuration can have different disk numbers.
For more information, see the following resources:


You can divide your hard drive into multiple partitions. You can create separate system, recovery, Windows, or data partitions.

To enhance the security of the Windows partition or a data partition, you can use BitLocker to encrypt the partition. For more information, see BitLocker Drive Encryption.

The partition types must match the firmware of the computer. You can install Windows® 8 and Windows Server® 2012 on hard drives that are based on any of the following types of firmware:

  • Basic Input/Output System (BIOS). Uses the Master Boot Record (MBR) partition structure.

  • Extensible Firmware Interface (EFI) (Class 1): Uses the GUID Partition Table (GPT) partition structure.

  • Unified Extensible Firmware Interface (UEFI) Class 2: Uses the GPT partition structure. Also includes a compatibility support module (CSM) that enables you to use BIOS functions, including the MBR partition structure. This module can be enabled or disabled in the firmware.

  • Unified Extensible Firmware Interface (UEFI) Class 3: Uses the GPT partition structure.

To determine your system type, consult your hardware manufacturer. For a full description of UEFI Class definitions, see UEFI.org: Evaluating UEFI using Commercially Available Platforms and Solutions.

System Partitions

A system partition is a partition that contains the hardware-specific files that are needed to load Windows.

By default, during Windows Setup, Windows stores these hardware-specific files in a separate partition. This enables the computer to use the following:

  • Security tools. Some security tools, such as BitLocker, require a separate system partition.

  • Recovery tools. Some recovery tools, such as Windows Recovery Environment (Windows RE), require a separate system partition.

  • Multiple operating systems. If a computer has multiple operating systems, such as Windows® 8 and Windows® 7, the computer displays a list of operating systems. The user can then select which operating system to boot. When the system boot files are on a separate partition, it is easier to remove a Windows partition or replace the partition with a new copy of Windows.

For information about how to configure system partitions while you apply images, see Capture and Apply Windows, System, and Recovery Partitions.

Microsoft Reserved Partition (MSR)

The MSR is used on UEFI/GPT systems, to support software components that formerly used hidden sectors.

For more information about configuring MSR partitions, see Configure UEFI/GPT-Based Hard Drive Partitions.

For more information about MSR partitions, see Windows and GPT FAQ

Recovery Partitions

A recovery partition might include a recovery solution such as Windows RE tools, a recovery image, and/or a third-party recovery tool. A recovery solution can help you reduce your support costs by enabling users to quickly restore a computer's factory settings.

We recommend adding Windows RE Tools, system and utility partitions before the Windows partition, because in the event that a full-system recovery is needed, this partition order helps to prevent the recovery tools from overwriting the system and utility partitions. For BIOS/MBR-based systems, we recommend that the Windows RE tools be included in the system partition to reduce the total number of partitions.

We recommend adding a partition with a separate recovery image after the Windows partition, because with this partition order, end users who want to reclaim this space for their primary partition may choose to remove this partition and then extend the Windows partition to fill the reclaimed space.

Data Partitions

A data partition is a partition that stores user data. A separate data partition can enable easier maintenance for situations where either the primary operating system is likely to be replaced, or when multiple operating systems exist on the same computer, such as, Windows® 8 and Windows® 7. When a computer has multiple hard drives, a data partition may be stored on another drive.


For typical single-drive configurations, we do not recommend that you use a separate data partition. There are two main reasons:

  • The partition may not automatically protect data that is stored outside the user profile folders. For example, a guest user might have access to files in an unprotected data partition.

  • If you change the default location of the user profile folders to any volume other than the system volume, you cannot service your image. The computer may not apply updates, fixes, or service packs to the installation. For a list of known issues related to changing the default folder locations, see Description of known issues with the FolderLocation settings.

See Also

Other Resources

Hard Drives and Partitions