You must be logged on as an administrator to perform these steps.

A boot partition is a partition that contains the files for the Windows operating system. If you want to install a second operating system on your computer (called a dual-boot or multiboot configuration), you need to create another partition on the hard disk, and then install the additional operating system on the new partition. Your hard disk would then have one system partition and two boot partitions. (A system partition is the partition that contains the hardware-related files. These tell the computer where to look to start Windows.)

To create a partition on a basic disk, there must be unallocated disk space on your hard disk. With Disk Management, you can create a maximum of three primary partitions on a hard disk. You can create extended partitions, which include logical drives within them, if you need more partitions on the disk.

Picture of disk space in Computer Management
Unallocated disk space

If there is no unallocated space, you will either need to create space by shrinking or deleting an existing partition or by using a third-party partitioning tool to repartition your hard disk. For more information, see Can I repartition my hard disk?

To create a boot partition


  • If you are installing different versions of Windows, you must install the earliest version first. If you don't do this, your computer may become inoperable.

  1. Open Computer Management by clicking the Start button Picture of the Start button, clicking Control Panel, clicking System and Security, clicking Administrative Tools, and then double-clicking Computer Management. Administrator permission required If you're prompted for an administrator password or confirmation, type the password or provide confirmation.

  2. In the left pane, under Storage, click Disk Management.

  3. Right-click an unallocated region on your hard disk, and then click New Simple Volume.

  4. In the New Simple Volume Wizard, click Next.

  5. Type the size of the volume you want to create in megabytes (MB) or accept the maximum default size, and then click Next.

  6. Accept the default drive letter or choose a different drive letter to identify the volume, and then click Next.

  7. In the Format Partition dialog box, do one of the following:

    • If you don't want to format the volume right now, click Do not format this volume, and then click Next.

    • To format the volume with the default settings, click Next.

    For more information about formatting, see Formatting disks and drives: frequently asked questions.

  8. Review your choices, and then click Finish.

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