Installing Windows on disks larger than 2TB

  • Article

Some friend raised an interesting topic: How do we boot Windows 7/8 on disks larger than 2TB?

My first guess would be simple: select "Repair your computer" before clicking "Install now" button, enter command prompt to load the disk driver & prepare disk with DISKPART.

But soon I realized installing & booting from disk larger than 2TB is not as easy as "pre-create partitions on a GPT disk in advance".

 

Short Answer

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After couple of unsuccessful attempts I finally made it. The secret is UEFI boot.

 

 

References

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Key Info

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  • GPT vs MBR: GPT for disks larger than 2TB is a must. Disks using MBR partitioning table can only support up to 2TB address space.

  • BIOS vs UEFI: All versions of Windows support BIOS firmware. On modern mainboards, UEFI became an standard option.

  • 2TB is NOT a limitation defined by NTFS. Actually NTFS can support up to 2^64 bytes which is 16 Exabyte.

  • Support Matrix:

System

BIOS + MBR

BIOS + GPT

UEFI + MBR

UEFI + GPT

Windows Vista & later

Supported

Boot volume not supported

Boot volume not supported

Supported; requires 64-bit version

Windows XP

Supported

Boot volume not supported

Boot volume not supported

Not supported

 

 

DISKPART?

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Unfortunately preparing partitions with diskpart.exe to is NOT a feasible option because:

  • Windows will automatically convert it back to MBR if it’s a GPT disk without partition;

  • or refuse to install on a GPT disk with one or more partitions.

Using Linux utilities such as gparted is all the same. Windows setup program simply incompatible with BIOS+GPT combination.

 

 

Resolution

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The correct solution is to enable UEFI boot support in BIOS setting and setup with modern Windows ISO such as Windows 8.1.

 

Note: if running on Hyper-V, UEFI is only available for Generation 2 VM on latest hypervisors:

 

Simply select the empty disk & hit “Next”

 

Here comes the wonder!

 

 

Tricks

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If you see this in UEFI boot, it means the ISO is corrupted, even if it works with BIOS boot. Try to download a new ISO (or copy the entire \efi folder from a working ISO. Unverified.).

 

If you can’t see the prompt while booting with setup CD,

Then do some tweak to the ISO. Navigate to \efi\microsoft\boot, swap file names:

 

Sometimes Secure Boot prevents boot on older ISO such as Vista/Win7. Uncheck it:

 

 

Wish it’s useful for you.