By Dylan / Last Updated October 12, 2020

Scenario

Why my 4TB drive only shows 2TB?

“I bought a 4 TB Seagate hard drive. But the drive only shows 2TB on the computer. Anyone knows how to find the other 2TB capacity?”

- Question from Tomshardware.com

Why 4TB hard drive only shows 2TB?

It is a common problem that 4TB (or 5TB, 6TB,etc) hard drive only shows 2TB, and the rest space is shown as an “unallocated” space in Disk Management. What’s worse, you can’t even use it to create other new volumes or partitions for data storage. At this moment, if you open Disk Management, you will find it is labeled as MBR disk.

There are 2 partition styles most commonly used to partition disk, MBR and GPT. They are different slightly in supported partition amounts, disk capacity, OS compatibility and boot mode. For example, GPT can support disk larger than 2TB but MBR partition style cannot. And this is why your 4TB hard drive only shows 2TB.

So, to restore all the capacity of the hard drive, you need to convert the MBR disk to GPT disk. In the following content, let me walk you through how to perform such a conversion.

How to fix “4TB Drive Only Shows 2TB” in Windows 10/8/7?

Here we provide two methods of converting MBR to GPT partition style; you can choose one based on your need.

1. Convert 4TB drive to GPT with Diskpart (data loss)

There is a built-in tool called Diskpart, which can convert 4TB hard drive to GPT with several lines of command. Here are the detailed steps.

✍Note: this method needs to clean your disk before converting, so if it is not a new hard drive or has important data on it, you have to back up the disk beforehand.

Step 1. Press “WIN+R”, type “CMD” and press Enter to open the command prompt. Then, input "diskpart" and hit Enter.

Step 2. Type the following commands, remember press Enter after you input each one.

  • list disk

  • select disk n (n means the drive letter, replace it with your 4TB drive letter)

  • clean (clear all partitions on the selected disk)

  • convert gpt

Diskpart Convert Gpt

When the “DiskPart successfully converted the selected disk to GPT format” shows on the screen, type “exit” and press “Enter” to leave the program, and check if the rest of the capacity is restored.

2. Convert 4TB drive to GPT via freeware (data safe)

Diskpart Command Line is an effective way to convert MBR to GPT for fixing “4TB shows only 2TB” issue in Windows 10/8/7, but it has an obvious disadvantage: you have to delete all existing partitions and data on the drive. Moreover, these command lines may be difficult to remember in a short time for computer beginners. And it is easy to input the wrong disk number and lose important files.

Fortunately, you can turn to AOMEI Partition Assistant Standard. It allows you to convert MBR disk to GPT without removing partitions and losing any data. In addition, thanks to its user-friendly operation interface, you don’t need to remember any command or complex operation. Now download the freeware and install it on your Windows computer, and see how to operate it.

Step 1. Open AOMEI Partition Assistant Standard. Right-click the 4TB drive you want to convert, and choose “Convert to GPT Disk”.

Convert 4tb To Gpt

Step 2. And click “OK”.

4tb Ok

Step 3. Then click “Apply” on the left top of the main interface.

4tb Apply

And wait a while, the hard drive will be converted to GPT disk, and you can use the full capacity of the hard drive.

✍Notes:
1. If the system partition encounter "4TB shows only 2TB" problem, you might need to convert boot disk between MBR and GPT partition style, and you can upgrade to AOMEI Partition Assistant Pro Edition.
2. To avoid data loss due to improper human operations or sudden power outage, backing up important data is always a great idea.

Conclusion

I believe the 2 methods can help you to fix “4TB drive only shows 2TB” in Windows 10/8/7. Both methods can be applied to different brands of storage drives, like Seagate, WD. But method 2 is more recommended, because you don’t need to delete any data on the drive, and you can keep lots of features in one tool, like resizing partition, merging partitions, copying partition, wiping hard drive, checking bad sector on a hard drive.

And If your computer is running with the Windows Server system, you can try AOMEI Partition Assistant Server Edition, which is specialized for Server system.