How to Increase C Drive Space in Windows Server 2022/2025

by John, Updated on: July 11, 2026

Low disk space on the C drive is an inevitable challenge for many administrators managing Windows Server 2022/2025. When this occurs, you can increase C drive free space without the need to repartition the disk or restore your system from a backup. To expand the C drive in Windows Server 2022/2025, you can utilize the native Disk Management utility if your current disk configuration meets its strict requirements. Otherwise, running safe disk partition software is required. This article introduces three efficient methods to increase C drive capacity in Server 2022/2025 while keeping your operating system, programs, and data completely intact.

Increase C drive space

1. Increase C Drive Space in Server 2022/2025 Without Software

As with previous versions, Windows Server 2022/2025 provides two native utilities to help extend partitions in Server 2022 and 2025. The DiskPart tool operates via the command line, while the Disk Management snap-in offers a graphical user interface (GUI). Although these tools function differently, they share the exact same architectural limitations. You can only extend the C drive without third-party software if your current disk configuration satisfies specific structural criteria.

  1. The C drive must be formatted with the NTFS file system.
  2. There must be adjacent unallocated space located directly on the right of the C drive.

How to increase C drive space in Windows Server 2022/2025 using native tools:

  1. Press the Windows key + X on your keyboard and select Disk Management from the menu.
  2. Right-click the adjacent D drive and select "Delete Volume".
  3. Right-click the C drive and select "Extend Volume". Follow the Extend Volume Wizard, clicking "Next" until you click "Finish".

When you shrink the D drive using Disk Management or the DiskPart command, the resulting unallocated space is generated on the right side of the D drive. Because this space is non-contiguous to the C drive, the "Extend Volume" option will be greyed out. This structural requirement explains why you must completely delete the D drive to obtain contiguous unallocated space on the right of the C drive.

Even if you are able to delete the D drive, another critical partition constraint applies. The D drive must be a Primary partition; otherwise, Disk Management cannot extend the C drive even after the partition is removed. If you cannot delete this companion volume, or if the adjacent partition is configured as a Logical drive, specialized disk partition software is required.

2. Increase C Drive Space from D/E Drive in Server 2022/2025

By utilizing specialized disk partition software, you can shrink the D drive or another volume to generate unallocated space on its left side. This allows the C drive to be extended seamlessly using the resulting contiguous unallocated space. To expand the C drive safely in Windows Server 2022/2025, using reliable software is paramount to avoid the risk of partition or system damage. To ensure maximum data protection, NIUBI Partition Editor integrates advanced data protection technologies to safeguard your entire server environment.

  1. Virtual Mode - Real disk partitions will not be modified until you click the "Apply" button to confirm the pending operations.
  2. Cancel-at-will - You can safely terminate ongoing operations at any stage without risking data corruption or partition destruction.
  3. 1-Second Rollback - If the utility detects any known system error while modifying partitions, it automatically reverts the server to its original state instantly.
  4. Hot-Clone - This feature enables online disk partition cloning without interrupting server availability, allowing regular background backups that are immediately bootable if the primary drive fails.

Option A: Increase C Drive Free Space from the D Drive

With NIUBI Partition Editor, partition type and file system constraints are completely eliminated. It seamlessly modifies volumes regardless of whether the D drive is Primary or Logical, or formatted as NTFS or FAT32. You simply need to shrink the volume to generate unallocated space on its left side, and then merge that unallocated space directly into the C drive.

Note: In this example, the D drive refers to the partition strictly adjacent to the right of the C drive. If you need to allocate free space from a non-adjacent partition, please refer to Option B below.

Upon Downloading and launching the utility, the main window will display all detected storage devices alongside their partition layouts and key volume parameters. In this demonstration environment, the C, D, and E drives reside on Disk 0, with ample free space available on both the D and E volumes.

NIUBI Partition Editor

How to increase C drive space in Windows Server 2022/2025 from the D drive:

  1. Right-click the D drive and select "Resize/Move Volume". In the pop-up window, drag the left border toward the right, or input a specific amount into the "Unallocated space before" field.
    Shrink D drive
  2. Right-click the C drive, select "Resize/Move Volume", and drag the right border toward the right to merge this newly generated unallocated space.
    Extend C drive
  3. Click "Apply" in the top-left corner to execute the pending operations and finalize the changes.
    C drive extended

Option B: Increase C Drive Free Space from the E Drive

If the contiguous D drive is also nearly full, you can allocate free space from the non-adjacent E drive. While the process is similar, it requires an extra step: you must first move the D drive to the right. This shifts the unallocated space so it is directly next to the C drive. Watch the video tutorial below to safely increase C drive free space in Server 2022/2025 from another partition.

Increase C drive

On certain servers, an EFI, Recovery, or other system partition may reside between the C and D drives. In such scenarios, you must move this intervening partition to the right as well. The C drive can only be expanded once the unallocated space is positioned strictly adjacent to it.

If you want to increase C drive space in VMware, Hyper-V, or VirtualBox environments running Server 2022/2025, follow the exact same steps detailed above. If the C drive is deployed on any hardware RAID array, avoid breaking the array or performing manual reconfigurations on the RAID controller. The process to resize a RAID partition remains completely identical to standard physical drives.

3. Increase C Drive Free Space with a Larger Disk in Server 2022/2025

If a physical disk is completely full, partition utilities cannot transfer capacity from a separate physical drive. To resolve this hardware limitation, you can clone the disk to a larger drive and extend the C drive using the extra disk space. Utilizing its Hot-Clone feature, NIUBI Partition Editor safely clones the entire disk directly within Windows without requiring a system reboot.

How to increase C drive space in Server 2022/2025 with a larger disk:

  1. Connect a larger storage drive to the server. If the source system disk is mechanical, it is highly recommended to clone it to an SSD.
  2. Right-click the leftmost area of the source disk and select the "Clone Disk" option.
  3. Select the larger destination disk from the list and click "Next".
  4. Edit the size and location of the target partitions (drag either border to resize, or the middle to move if adjacent unallocated space is available). Always begin your adjustments from the last partition on the right.

For a comprehensive step-by-step visual demonstration of this process, watch the accompanying video tutorial.

Beyond shrinking partitions and increasing C drive capacity in Windows Server 2022/2025 and legacy versions from Server 2003 to 2019, NIUBI Partition Editor provides a comprehensive toolkit to clone, convert, merge, hide, and wipe partitions, as well as optimize file systems and scan for bad sectors.

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