How to Install Windows 10 on a GPT Disk

To install Windows 10 on a GPT disk, start the PC from a Windows 10 installation USB in UEFI mode. In Setup, choose Custom, delete the old partitions on the drive, select the Unallocated Space, and select Next. Setup creates GPT partitions for you.

Applies to: Windows 10. Checked against Microsoft Learn on September 28, 2026.

Before you start

• A clean install erases the drive. Back up your files first. See how to back up Windows 10.
• Check the disk’s partition style. Open Disk Management, right-click the disk (for example Disk 0), and select Properties > Volumes. See how to open Disk Management in Windows 10.

• You need an installation USB. See how to create a bootable Windows 10 USB drive.

Install Windows 10 on GPT

1. Make sure the PC’s firmware is set to UEFI mode, not Legacy or CSM. See how to enter BIOS or UEFI in Windows 10.
2. Start from the USB. In the boot menu, choose the entry that starts with UEFI:. See how to change the boot order in Windows 10.
3. In Setup, select Install now, then Custom: Install Windows only.
4. Select each partition on the drive you’re installing to and select Delete. This erases it.
5. Select the Unallocated Space and select Next. Setup makes the drive GPT and finishes installing.

If Setup says “The selected disk is of the MBR partition style”, the PC started in UEFI mode but the disk is still MBR. Deleting all partitions on that drive, as in step 4, fixes it.

Convert the disk to GPT during Setup

If Setup won’t install because the disk is MBR, you can wipe it and convert it from Setup itself. This erases everything on the disk.

1. On the Setup screen, press Shift + F10 to open Command Prompt.
2. Type diskpart and press Enter.
3. Type list disk and note the number of the disk you want to use. Check the size to be sure.
4. Type select disk 0, using your disk number.
5. Type clean, then convert gpt, then exit.
6. Close Command Prompt, select Refresh in Setup, and pick the Unallocated Space.

Convert an existing Windows 10 drive without erasing it

Windows 10 version 1703 and later includes MBR2GPT, which converts the system drive and keeps your files. Back up first anyway.

1. Open Command Prompt as administrator.
2. Run mbr2gpt /validate /allowFullOS. Continue only if it says Validation completed successfully.
3. Run mbr2gpt /convert /allowFullOS.

4. Restart, go into your firmware settings, and switch from Legacy/CSM to UEFI.

Troubleshooting Setup errors

• “The selected disk is of the GPT partition style.” The PC started the USB in Legacy mode. Restart, open the boot menu, and choose the USB entry that starts with UEFI.
• “The selected disk has an MBR partition table. On EFI systems, Windows can only be installed to GPT disks.” The PC is in UEFI mode but the disk is MBR. Delete all partitions on that disk in Setup, or convert it with diskpart as shown above.
• “We couldn’t create a new partition or locate an existing one.” Unplug other drives and USB storage except the installer, then try again. If it still fails, run diskpart clean on the target disk.
• There’s no UEFI entry for the USB. The USB was made for Legacy BIOS only. Recreate it with Microsoft’s Media Creation Tool, which works in both modes.
• MBR2GPT says “Disk layout validation failed.” The disk has too many partitions or no free space for the new system partition. Back up and do a clean install instead.

Frequently asked questions

What’s the difference between GPT and MBR?

GPT is the newer style. It works with UEFI, supports drives bigger than 2 TB, and is needed for features like Secure Boot.

Do I need Secure Boot?

It’s a good idea once you’re on UEFI. See how to turn on Secure Boot in Windows 10.

Can I install Windows 10 on GPT without UEFI?

No. On a PC that only supports Legacy BIOS, Windows 10 needs an MBR disk. For a data disk that isn’t the boot drive, GPT works in either mode.

Will a GPT disk help me upgrade to Windows 11?

Yes. Windows 11 needs UEFI with Secure Boot support, which requires a GPT system disk. Windows 10 no longer gets regular updates, so it’s worth checking whether your PC can upgrade.

Microsoft’s reference is Windows Setup: Installing using the MBR or GPT partition style. More help is on our Windows Help & Guides page.

Related: set up RAID 0 in Windows 10.