How to Repartition Hard Drive without Losing Data in Windows 10/8/7?

January 29, 2018

Want to partition your hard drive for other purposes like installing Windows 7? Come and see how to repartition a hard drive without losing data in Windows 10/8/7.

When need to repartition a hard drive?

When you have different plans for a used hard drive, you need to repartition it. Repartition a hard drive means you’ll re-allocate partition size, drive letter and file system. Generally speaking, you may want to repartition a hard drive in following situations.

  • Resize partition. A general repartition could be simply resizing existing partitions to satisfy the need. Resize to generate unallocated space and then create new partition with that space. Or, resize to generate free space and then add it to another space-needing partition.  

  • Partition hard drive for Mac and PC Windows. It is necessary do repartitioning if you’d like to install dual-boot operating systems. You’ll need at least two primary partitions that are large enough and formatted with different file systems to store the OS. Except for Mac and Windows, many users tend to dual boot Windows 7 and Windows XP, Windows 10 and Windows 7, etc.

  • Partition hard drive before installing Windows 7. You may want to partition a hard drive before you install a new operating system. Sometimes, the behavior solves the issue that hard drive not recognized while installing Windows.

You may need to repartition a hard disk under other situations that haven’t been listed here. However, what counts next is to figure out how to repartition a hard drive for the best.

How to repartition hard drive in Windows 10/8/7 step by step?

Windows brings you internal device manager that allows you to partition hard drive external or internal. You can complete the task with the help of Disk Manager or Diskpart. Let’s take a closer look.

Partition hard drive in Disk Management

Right click My Computer, Computer or This PC and select Manage to open Disk Management. You’ll see partition status, drive letter, file system, used space and other necessary factors right there.

1. To extend partition: if there is unallocated space adjacent to the partition you want to extend, you can do the extending. Right click the partition and select Extend Volume. Follow the wizard to perform extending.

Extend Volume Device Manager

If there is no contiguous space next to that partition, or even no unallocated space on that disk, you’ll find Extend Volume grayed out. Learn how to extend partition to non contiguous space.

2. To shrink partition: right click the partition and select Shrink Volume. You should be able to shrink the partition to half of the partition size. If you want to shrink a partition size more than a half, refer to shrink C drive beyond half.

3. To create new partition: right click an unallocated space and select New Simple Volume. Follow the wizard to complete the creating. You can get unallocated space by deleting existing partitions, but be sure to backup important files before you start.

If you want to completely repartition a hard disk, you can delete all existing partitions to let the unallocated space into one. Then, do the dividing and creating. Nevertheless, that can be done on external hard drive only because Windows does not allow you to delete system partition under Windows environment. It also goes to formatting a partition with another file system.

Repartition hard drive Command Prompt

You can do hard drive partitioning using CMD, a more direct method for advanced users.

1. Press Windows key + R key to open Run. Type diskpart and run as administrator.

2. To resize partition, type: list volume > select volume n (where n is the number of the partition you want to change) > extend size=10240 (in MBs) > exit. You can replace extend with shrink. Each command follows an Enter.

Diskpart Extend Volume

3. To format a specific partition, type: format fs=ntfs (or fat32) after you select the drive.

Tips: You can type: /? to see what diskpart can do for you. Generally, more options than Disk Management can offer. For more information about diskpart.exe, check out Diskpart Windows 10.

How to repartition hard drive without losing data?

Except for extend and shrink volume, all operations have risk of losing stored data. To be specific, to give a drive with different file system, you need to format it. To add unallocated space to partition that is separated, you need to delete the obstacle partition.

Fortunately, you can do those tasks without losing any data with the help of AOMEI Partition Assistant Professional (Windows 10/8/7/XP/Vista supported). You are able to allocate free space from one partition to another directly with no need to shrink and then extend; create new partition directly from existing redundant partition; change file system without formatting between NTFS and FAT32; quick partition a hard drive with several partitions in one click; partition internal disk without booting Windows with created bootable media; and more.

Here are the steps for you to resize drives (shrink system volume and create another without losing data):

Step 1. Free download AOMEI Partition Assistant and open it. You will get the main interface:

PA main interface.gif

Step 2. Right click on the volume C or the drive you want to reallocate. Then, select "Resize Partition".

Resize Partition.gif

Step 3. Drag drive C from right to left in order to release some free space. After that, please select "OK".

Move and Resize Partition.gif

Step 4. Right click the unallocated space and select "Create partition". Fill in the detail of the new volume you want to build, then, click "OK".

Create Partition.gif

Step 5. Do not forget to select "Apply" on the toolbar to make sure these operations come into an effect.


Tips: With this Professional edition, you can allocate free space from one volume to the other directly. What’s more, if you can create a partition from C drive in Windows 7 or 10 without resizing.

As stated, you can quick partition a hard disk into several different partitions simultaneously. Right click the disk you want to partition and select Quick Partition from the given list. You’ll see a window below. Configure each partition as you wish.

Quick Partition window

Repartition hard drive without formatting or losing data can be easily achieved. If you want to manage hard disk and reallocate a hard drive for your Windows Server 2000/2003/2008, you can use AOMEI Partition Assistant Server Edition, a server partition magic. It is also a best choice to choose AOMEI Partition Assistant Pro Edition for personal user or business PC owner work on Windows 7/2000/XP/Vista.