By Dervish / Last Updated November 10, 2022

Need to extend C drive on Server 2012

Server 2012

C drive, also named as system drive, is an extremely important part on the (Server 2012) computer since the operating system is usually installed on this drive or partition. Besides the operating system, there are also many vital files, such as temporary files, browser caches, downloaded programs, applications, etc. being saved on this partition.

As a result, C drive might be running out of space quickly with time going by. Well, when your C drive is almost full and received the low disk space alert, apart from free up space on C drive via move apps to another drive, delete unnecessary files, etc., most users might consider extending system C drive by adding more space to it from other volumes. For this task, you can make use of two tools: Windows native Disk Management and third party partition manager.

Next, I'm glad to show you full solutions with 2 ways to help increase C drive space Server 2012. Select a corresponding tool and method based on your disk partition configuration.

How to extend C drive in Windows Server 2012 via Disk Management

Disk Management in Windows Server 2012 is a built-in tool for users to manage their disk partitions in a graphical interface. If there is an adjacent unallocated space after the C drive, you can directly right-click C drive, choose “Extend Volume” and follow the wizard to extend the Server OS drive.

Warning: If there is no contiguous unallocated space, the “Extend Volume” option will be greyed out. In this situation, you have to first delete the partition after the system drive.

Here is how to perform it:

Step 1. Open Disk Management: press Win+R to open Run program. In the Run dialog, type diskmgmt.msc and press Enter key.

Step 2. Right-click the E drive (which locates after C drive) and select “Delete Volume” from the menu.

Delete E Drive

Step 3. After deleting E drive, it will turn into an unallocated space. Now, right-click the C drive and select “Extend Volume”.

Extend C Drive

Step 4. In the Extend Volume Wizard, click "Next" to continue.

Extend Volume Wizard

Step 5. Select the disk from which you need to take free space to C drive. And click “Finish”.


Although Windows Server 2012 Disk management can shrink and extend volumes, both of them come with restrictions:
The “Shrink Volume” function can only make unallocated space on the right after shrinking a volume.
The “Extend Volume” feature only functions when the unallocated space is directly behind the target drive you need to extend.
In brief, the “Extend Volume” option can only add the unallocated space to the left contiguous partition. Therefore, if you want to expand C drive in Server 2012, the only option is to delete the right adjacent volume. As shown above, to extend C drive, you have to delete E drive first. How tiresome! What's worse, it will lead to the disaster of data loss.

Easily extend C drive on Server 2012 with partition software

When the Disk Management lets you down, or if you don’t want to delete partition after the system drive, you can try AOMEI Partition Assistant Server. This Server partition software is compatible with both Windows Server and Windows PC. It breaks out the limitations of Disk Management and can do:

 Move partition to make unallocated space contiguous to the target volume;
 Extend volume with both the right and left contiguous unallocated space;
 Merge non-adjacent unallocated space into another partition;
✦ Allocate free space from one partition to another.

In addition to the above 4 amazing features, AOMEI Partition Assistant Server has another more advanced feature called “Extend Partition Wizard”, designed for easily extending NTFS system partition without data loss. Besides, it does not require you to reboot the system after extending C drive on Server 2012. There is a demo version for free download and trial.

Download Demo Server 2008/2012/2016/2019/2022
Secure Download

Step 1. Install Partition Assistant Server Edition and open it. In the main interface, choose the option of "Extend Partition Wizard" to launch it, and click “Next”.

Extend Partition Wizard

Step 2. Here, select “Extend system partition” from the given two options. Click “Next”.

Extend System Partition

Step 3. Choose a partition from which you plan to take free unallocated space. Here we select D drive and hit on “Next”.

Select D Partition

Step 4. In the following window, drag the slider bar to the right to free space, or you can enter a proper value into the Partition New Size box.

Extend C Drive

Step 5. This interface will give us the detailed information about the operation of volumes. Please choose "Proceed" to execute all these operations.


After executing all these operations, you can see the C drive becomes larger, and the system will not reboot.


Much better and more versatile than Disk Management, AOMEI Partition Assistant Server can help extend C drive on Server 2012 or extend C drive Server 2012 R2 in several safe and easy ways. How convenient it is! Just several clicks and drags can increase C drive space on Server 2012! Meanwhile, it also supports cloning Server OS to SSD, cloning partition, converting (boot) disk between MBR and GPT without deleting partitions, etc.  

If you need to install it on multiple PCs and Servers, you can consider the AOMEI Partition Assistant Technician or Unlimited edition based on your needs. The Technician and Unlimited edition have a helpful function, Create Portable Version, enabling you to create AOMEI Partition Assistant to a removable device. Thus, you can connect the device to other computers and run AOMEI Partition Assistant from the device without installation.