Installing Windows 10 on a custom partition
Partitioning

How to create custom partition to install Windows 10

You can create and install Windows 10 on a custom partition, and in this guide, we'll show you how to do it.

Although you can resize a partition at any time on Windows 10, if you’re planning to create a dual boot system, or you want to keep your files separate from the main installation, you can create a custom partition for Windows 10 and apps during the installation process.

In this guide, you’ll learn the steps to create and install a clean copy of Windows 10 on a custom partition.

How to partition a drive during installation of Windows 10

To install Windows 10 on a custom size partition, use these steps:

Important: To start your device with a bootable media, you need to change the BIOS settings. This process usually requires pressing one of the function keys (F1, F2, F3, F10, or F12), the ESC or Delete key. For more accurate instructions, visit your PC manufacturer’s support website. Also, this process will delete everything on the hard drive, as such it’s recommended to backup any files before proceeding.
  1. Start your PC with the USB bootable media.

  2. Press any key to begin.

  3. Click the Next button.

  4. Click the Install now button.

    Windows 10 Install now button
    Windows 10 Install now button
  5. Type the product key, or click the Skip button if you’re reinstalling.

    Windows 10 setup, product key settings
    Windows 10 setup, product key settings
  6. Check the I accept the license terms option.

  7. Click the Next button.

  8. If you skipped the product key, select the edition of Windows 10 that you’re about to install.

    Windows 10 setup, select edition to install
    Windows 10 setup, select edition to install
  9. Click the Next button.

  10. Select the Custom: Install Windows only (advanced) option.

    Windows 10 setup, custom install option
    Windows 10 setup, custom install option
  11. Select each partition in the hard drive that you want to install Windows 10 and click the Delete button. (Usually, the “Drive 0” is the drive that contains all the installation files.)

    Warning: Deleting a partition also deletes all data within.
  12. Select the Drive 0 Unallocated Space and click the New button.

    Windows 10 setup, create custom partition
    Windows 10 setup, create custom partition
  13. Specify the amount of space (in megabytes) to allocate for the installation of Windows 10 and apps. (The operating system requires at least 20GB of space, but to prevent problems with future updates and running out of pace to install applications, you should be creating a partition between 60GB to 100GB in size.)

    Windows 10 setup, specify partition size
    Windows 10 setup, specify partition size
  14. Click the Apply button.

  15. Click the OK button. (Alongside the custom partition, Windows 10 will also additional partitions automatically required to install and run the operating system.)

  16. (Optional) Select the Drive 0 Unallocated Space and click the New button to create additional partitions with the remaining space. However, this is a task that you can always perform after the installation.

  17. Select the Drive 0 Partition 4 (Primary) from the list and click the Next button.

    Select partition to install Windows 10
    Select partition to install Windows 10

Once you’ve completed the steps, the setup will proceed to install Windows 10 on the custom partition that you created.

After the installation, you’ll need to go through the out-of-box experience (OOBE) to create an account and finish configuring the installation.

Creating partition with remaining unallocated space

If you didn’t use the remaining space, you can use these steps to create an additional partition to store files and other items.

  1. Open Start.

  2. Search for Disk Management, click the top result to open the experience.

  3. Right-click the unallocated space in the drive and select the New Simple Volume option.

    Disk Management, New Simple Volume option
    Disk Management, New Simple Volume option
  4. Click the Next button.

  5. Specify the amount of space (in megabytes) for the partition in megabytes.

    Specify partition size for a new drive
    Specify partition size for a new drive
  6. Click the Next button.

  7. Use the “Assign the following driver letter” drop-down menu, and select a letter to make the drive available in File Explorer.

    Assign drive letter to new partition on Windows 10
    Assign drive letter to new partition on Windows 10
  8. Click the Next button.

  9. Select the Format this volume with the following settings option.

  10. Use the “File system” drop-down menu, and select the NTFS option.

  11. In the “Allocation unit size” setting, leave the Default option.

  12. In the “Volume label” field, type a name for the drive. For example, Data.

  13. Check the Perform a quick format option.

    New partition format settings on Windows 10
    New partition format settings on Windows 10
  14. Clear the Enable file and folder compression option.

  15. Click the Next button.

  16. Click the Finish button.

After completing the steps, the partition should will format with the settings you specified, and it should now be available for use in File Explorer.