By Lucas / Last Updated November 18, 2022

About BitLocker partition

BitLocker partition refers to the partition that's locked by BitLocker encryption tech which is a full-volume encryption capability that comes standard with Microsoft Windows versions beginning with Windows Vista. It interacts with the operating system and solves the risks of data theft or exposure caused by lost, stolen, or improperly retired devices.

BitLocker partition

If you're using TPM 1.2 or later, this feature can provide optimum data security. The TPM is a hardware component used by computer manufacturers in many modern devices. It works with BitLocker to protect user data and ensure that a computer was not tampered with after the system was shut off.

Why need to resize BitLocker partition?

Although BitLocker feature can protect the data, it also brings a problem: Users are not allowed to resize Bitlocker partition via Disk Management without decryption. So, if the locked drive is almost full of data and you want to extend BitLocker partition or shrink the BitLocker partition to use the free space to extend another drive, you’ll have to decrypt it at first.

BitLocker full

How to resize BitLocker partition in Windows 10?

As we mentioned above, to resize BitLocker partition in Windows, the first part is to unlock it. So, we’ll show you how to unlock your Bitlocker partition in Part 1, and in Part 2 we will show you how to resize BitLocker partition.

Method 1. Resize BitLocker partition via Windows tools

▶ Part1. Unlock BitLocker partition

Way 1. Unlock Bitlocker drive in Settings

Step 1. Open Settings and type “encryption”, and click “Manage BitLocker”.

Encryption

Step 2. You’ll get a popup and choose the drive and click “Turn off BitLocker”.

Choose locked drive

Step 3. Click “Turn off BitLocker” to confirm.

Turn off BitLocker

The drive is now unlocked.

Way 2. Unlock Bitlocker drive via CMD

Using CMD to decrypt a Bitlocker drive requires you to type the command:

• manage-bde -unlock d: -password

Then press “Enter” to confirm it.

Unlock CMD

▶ Part 2. Resize unlocked Bitlocker partition in Disk Management

After you manually unlock the BitLocker partition, now you can resize it in Disk Management. To extend the partition via Disk Management, there must have unallocated space on the adjacent right of the target partition. Otherwise, the extended option will be greyed out.

Step 1. Right-click on “This PC” on your desktop, select "Manage", and click on "Disk Management".

Step 2. Right-click on the partition you want to extend.

Step 3. Select “Extend Volume”. Then you can follow the guide to add volume to the target partition. If the target partition is a C drive, you might need to reboot your computer to complete the process.

Extend volume

Note: If you want to shrink the partition, please choose “Shrink Volume”.

Method 2. Easily resize BitLocker partition with a free third-party tool

If you successfully unlock the BitLocker partition with the above two ways, then resizing it will be much easier. However, some users confront a failure to unlock the BitLocker encrypted drive even if the password is correct. And part of the users finds that they can't shrink that partition over half size, or the “Extend Volume” selection is unavailable.

Thus, to offer you more solutions to resize a BitLock partition in Windows 10, here, we recommend you AOMEI Partition Assistant Standard, a free Windows disk and partition manager for Windows 11/10/8/8.1/7/XP computers.

The "Resize/Move Partition" function allows users to easily unlock BitLocker partition with a few clicks. So, you can easily adjust the partition size or create a new partition on your disk.

Download FreewareWin 11/10/8.1/8/7/XP
Secure Download

Now we'll show you how to use this handy tool to simply and safely resize the BitLocker partition in Windows 10.

▶ Shrink BitLocker partition

Step 1. Right-click the BitLocker encrypted partition and select “Resize/Move Partition”.

Resize BitLocker partition

Step 2. Drag the bar to resize the partition, and click on “OK” and "Yes" in the pop window to continue.

Drag to resize

Step 3. Click "Apply" and "Proceed" to confirm the operation.

Proceed

Step 4. Wait for a while to finish the task.

Finish resize

After you shrink the BitLocker partition, you can use the unallocated space from the BitLocker partition to create a new partition or extend C drive.

▶ Extend BitLocker partition

To extend the BitLocker partition, there must have unallocated space adjacently before or behind the BitLocker encrypted partition. Of course, you can also use the "Resize/Move Partition" function to realize it.

Step 1. Select an adjacent partition of the Bitlocker partition, and choose "Resize/Move Partition".

Create unallocated space

Step 2. Drag the size to create unallocated space.

Shrink adjacent partition

Note:
1. If the BitLocker partition is on the right of the selected partition, you need to drag towards the left to create unallocated space before the BitLocker space.
2. If the BitLocker partition is on the left of the selected partition, please drag towards the right to make unallocated space behind the BitLocker space.

Step 3. After you created unallocated space, now you can select the BitLocker partition and choose "Resize/Move Partition" again.

Apply

Step 4. Drag the size to extend the partition. And click "Yes"

Extend BitLocker partition

Step 5. Click "Apply" and "Proceed" to confirm the operation.

Apply

When the operation is finished, the BitLocker partition is extended.

Ending

To resize the Bitlocker partition in Windows 10, you need to do more work to unlock and resize it with system built-in tools. With AOMEI Partition Assistant, you can easily unlock and resize the BitLocker partition with easy operation in one tool, which makes the process more convenient.

And if you upgrade to the Professional Edition, there are many other functions like GPT/MBR conversion, cloning disk, changing file systems without formatting, moving installed programs, etc.