How to format 6TB hard-drive

Convert the 6 TB drive from MBR to GPT, then create a new simple volume; MBR cannot address capacity beyond approximately 2 TB, whereas GPT supports the drive’s full capacity.^1^

Important: protect existing files

The built-in conversion procedure requires deleting every volume on that disk, which erases access to its existing data. Back up anything you need before proceeding and carefully identify the 6 TB disk. Administrator rights are also required.^2^

If inaccessible files need to be recovered, do not format, delete volumes, or convert the disk yet. Copy or recover the data first.

Convert the drive using Disk Management

1. Right-click Start and select Disk Management.
2. In the lower pane, locate the 6 TB drive by its reported capacity. Do not select the Windows system disk.
3. Right-click the disk’s label on the left, such as Disk 1, select Properties, and open Volumes.
4. Check Partition style:
   • If it says Master Boot Record (MBR), continue below.
   • If it already says GUID Partition Table (GPT), do not delete it; the 2 TB issue has another cause.
5. After backing up its data, right-click each volume on the 6 TB disk and select Delete Volume until the entire disk is unallocated.
6. Right-click the disk label on the left—not the unallocated area—and select Convert to GPT Disk.
7. Right-click the resulting Unallocated area and select New Simple Volume.
8. Accept the maximum size, assign a drive letter, and format it with the wizard’s default settings.
9. Reopen Properties > Volumes and verify that Partition style is GUID Partition Table (GPT). Disk Management should now show the drive’s full available capacity as one usable volume.^2^ ^3^

If the disk is new and uninitialized

In Disk Management, right-click the disk label, select Initialize Disk, choose GPT (GUID Partition Table), and then create a New Simple Volume from the unallocated space. Do not choose MBR.^1^

If Disk Management reports the physical disk itself as only 2 TB even before partitioning, the enclosure, USB adapter, storage controller, or its driver may not support drives larger than 2 TB. Check the enclosure/controller specifications and obtain the applicable storage driver from its manufacturer.^1^

References

1. Windows support for hard disks that are larger than 2 TB
2. Convert a disk to GPT or MBR partition scheme
3. Disk Management in Windows | Microsoft Support