How to Extend C Drive on Windows Server & PC

By James, Updated on: January 22, 2020

This article introduces how to extend C drive space without formatting or losing data, 3 ways to extend c drive volume with detailed steps.

Applies to: Windows 10, Windows 8, Windows 7, Windows Vista, Windows XP, Windows Server 2019, Windows Server 2016, Windows Server 2012 (R2), Small Business Server 2011, Windows Server 2008 (R2) and Windows Server 2003 (R2).

To Windows computer users, the most common issue is that system C drive running out of space. Besides freeing up disk space, the best method is extending C drive with Unallocated space or free space in other volume. To extend C drive space for Windows server and PC, there are 3 tools: DiskPart command, Windows Disk Management and NIUBI Partition Editor. This article introduces detailed steps to expand system C drive with each tool.

How to extend C drive space with Disk Management

In Disk Management of Windows 10/8/7/Vista and Server 2019/2016/2012/2008, there is built-in Extend Volume functionality, which can be used to extend C drive without losing data. However, it only works under restricted condition, because it has many limitations such as:

  1. C drive should be NTFS. (Another common FAT32 partition is not supported)
  2. There must be adjacent Unallocated space on the right side of C drive.
  3. The right contiguous drive (D:) should be Primary partition.

If your disk partition configuration doesn't meet the requirements, Extend Volume is greyed out and disabled.

Steps to extend C drive partition with Disk Management:

  1. Transfer all files in the right contiguous partition (D) to other place.
  2. Press Windows and R keys together, type diskmgmt.msc and press Enter to open Disk Management.
  3. Right click D: drive and select Delete Volume, then its space will be converted to Unallocated.
  4. Right click C: drive and select Extend Volume, click Next till Finish in pop-up Extend Volume Wizard.

Do not delete drive D if you installed programs in it.

You can't extend C drive in Disk Management by shrinking D or any other volume, because you won't get right contiguous Unallocated space to enable Extend Volume function.

How to expand C drive volume with DiskPart command

DiskPart is working from command prompt, which is more difficult than Disk Management. To extend C drive with DiskPart, your disk partition configuration must meet the same requirements listed above. In Windows XP and Server 2003, there's no Extend Volume function in Disk Management, so if you don't want to use third party software, diskpart command is the only option.

Diskpart doesn't show Unallocated space and disk partition structure, it only display all partitions in a list.

Steps to extend C drive volume with diskpart command prompt:

  1. Transfer all files in the right contiguous drive D to other place.
  2. Press Windows and R together on the keyboard, type diskpart and press Enter.
  3. Type list volume and press Enter in diskpart.exe command prompt window.
  4. Type select volume D and press Enter. (D is drive letter or number of the right contiguous partition.)
  5. Type delete volume and press Enter.
  6. Type select volume C and press Enter.
  7. Type extend and press Enter.

In a short time, diskpart reports successfully extended the volume. Type list volume again, as you see, my C drive is increased from 40GB to 110GB.

Diskpart extend C

Extend C drive on Windows 10/8/7 with free partition software

With NIUBI Partition Editor, there are no such limitations. You can extend C drive by shrinking D or other partitions on the same disk, therefore, Operating System, programs and anything else keep the same with before. You just need to drag and drop on the disk map. To Windows 10/8/7/Vista/XP home computer users, there's free edition.

Download NIUBI Partition Editor Free and follow the steps in the video to extend C drive space:

Video guide

Extend C drive on Windows Server 2019/2016/2012/2008/2003

There's no difference to shrink partition and extend C drive on Windows server, no matter you use physical hard disk, any types of hardware RAID array or VMware/Hyper-V virtual disk. Better than other server partition software, NIUBI Partition Editor is much safer and faster because of the innovative technologies such as:

Besides shrinking and extending partition, NIUBI Partition Editor helps do many other disk partition management operations.