How to Configure BIOS/MBR-Based Hard Drive Partitions
Published: February 29, 2012
Updated: May 31, 2012
Applies To: Windows 8, Windows Server 2008 R2, Windows Server 2012
This topic describes how to configure hard drive partitions including hard disk drives (HDDs), solid-state drives (SSDs), and other drives, for a BIOS-based computer.
In this topic:
When you deploy Windows® to a BIOS-based computer, you must format hard drives by using an MBR file system. Windows does not support the GUID partition table (GPT) file system on BIOS-based computers.
An MBR drive can have up to four standard partitions. Typically, these standard partitions are designated as primary partitions. For information about how to create additional partitions beyond this limit, see How to Configure More than Four Partitions on a BIOS/MBR-Based Hard Disk.
Windows partition requirements:
System partition (with Windows RE tools)
Each bootable drive must contain a system partition. The system partition must be configured as the active partition.
The Windows Recovery Environment (Windows RE) tools image should be in a separate partition than the Windows partition to support automatic failover and to support booting Windows® BitLocker® Drive Encryption-encrypted partitions.
To avoid the four-partition limit on BIOS-based systems, we recommend adding the Windows RE tools image onto the system partition.
The minimum size of this combined partition is 350 MB. This partition must allocate space for system files (at least 50 MB), and for the Windows RE tools image (winre.wim, at least 250 MB), plus enough free space so that the partition can be captured by backup utilities:
If the partition is less than 500 MB, it must have at least 50 MB of free space.
If the partition is 500 MB or larger, it must have at least 320 MB of free space.
If the partition is larger than 1 GB, we recommend that it should have at least 1 GB free.
- If the partition is less than 500 MB, it must have at least 50 MB of free space.
Other utility partitions
Any other utility partitions must be located before the Windows, data, and recovery image partitions. This allows end users to perform actions such as resizing the Windows partition or reclaiming the recovery image partition without affecting system utilities.
Windows partition and other data partitions
This partition must have at least 20 gigabytes (GB) of drive space for 64-bit versions, or 16 GB for 32-bit versions.
This partition must have enough 10 GB of free space after the user has completed the Out Of Box Experience (OOBE).
This partition must be formatted using the NTFS file format.
- This partition must have at least 20 gigabytes (GB) of drive space for 64-bit versions, or 16 GB for 32-bit versions.
Recovery image partition
When used, this partition includes the Windows recovery image used by push-button reset utilities (install.wim).
The size of this partition must include space for the Windows recovery image (at least 2 GB), plus enough free space so that the partition can be captured by backup utilities:
It must have at least 320 MB of free space.
We recommend that it should have at least 1 GB free.
- It must have at least 320 MB of free space.
This section describes the default partition configuration and the recommended partition configuration.
The Windows Setup default configuration has a system partition and a Windows partition. This configuration allows BitLocker Drive Encryption to be enabled, and Windows RE to be stored in the hidden system partition. The following diagram shows the default configuration.
You can use this configuration to add system tools such as Windows® BitLocker® Drive Encryption and Windows Recovery Environment (Windows RE) to your customized Windows installation.
This recommended configuration includes a system partition, a Windows partition, and a recovery image partition. The following diagram shows the recommended configuration.
Add the system partition before you add the Windows partition. Add the partition that contains the recovery image at the end. Copy the Windows RE tools into the System partition, and copy the Windows RE recovery image into the Recovery Image partition. This partition order helps keep the system partition and the Windows RE tools safe during actions such as removing the recovery image partition or changing the size of the Windows partition.
By default, system partitions do not appear in File Explorer. This helps protect end users from accidentally modifying a partition.
When you are deploying Windows by using Windows Setup, use an answer file to configure your partitions. For the utility partition, set the Microsoft-Windows-Setup\DiskConfiguration\Disk\ModifyPartition\TypeID value to 0x27.
When you are deploying Windows by using the DiskPart tool, use the set id=27 command after you create the partition.
Click Start, right-click Computer, and then click Manage. The Computer Management window opens.
Click Disk Management. The list of available drives and partitions appears.
In the list of drives and partitions, confirm that the system and utility partitions are present and are not assigned a drive letter.
The following files contain XML samples that demonstrate how to set up partitions on a BIOS-based and MBR-based computer.
Demonstrates how to add answer-file settings to automatically configure drive partitions during Windows installation.
Demonstrates how to configure partitions by using a DiskPart script to prepare to deploy a Windows image to a new computer.