By Emily / Last Updated December 2, 2019

Necessary to resize system partition in Server 2003

The Server 2003 system partition is a partition that contains the Windows Server 2003 operating system located and crucial boot files. Compared with data drives, the system partition is more likely to run out of disk space. When your Server 2003 system partition has just a little space left, your computer will run very slowly, and you will spend a long time to boot up the OS and programs, or open the files/folders. Thus, it is necessary to extend system partition in Server 2003.

Besides, if you have given too much space to C drive when installing Server 2003 system on a new disk, you might want to shrink it smaller for creating new partitions to make better use of the disk space.

How to resize system partition in Windows Server 2003 (R2)?

To adjust system partition size on Windows Server 2003, you can use Windows Server 2003 DiskPart and a third-party Server disk partition management software.

Method 1. Use Diskpart to change system partition size in Server 2003

In general, Windows Server users could use Disk Management tool to extend or shrink system partition. However, in Windows Server 2003 Disk Management, there are no “Extend Volume” and “Shrink Volume” options (as the following screenshot).

Server 2003 Disk Management

In this situation, the DiskPart service is a nice alternative. It is a command-line tool, enabling users to deal with some partition management issues. If you are familiar with computer commands, you can follow the steps below to resize system partition in Windows Server 2003 via DiskPart.

Part 1. To extend system partition on Server 2003

To complete this task via DiskPart, there are 3 preconditions you have to note and satisfy:
1. The file system of the system partition must be NTFS.
2. There's unallocated space followed to the NTFS system partition. Otherwise, you need to delete the partition following the system partition.
3. This operation has to be executed before Windows is running.

Step-by-step guide on how to extend Server 2003 system partition using DiskPart:

Step 1. Boot your computer from the installation disk and press F2 or other access keys according to the hint from the start screen.

Step 2. Choose Command Prompt from the given options and type “diskpart” to launch this tool.

Step 3. Then type the following commands in sequence and press on “Enter”.

  • list volume

  • select volume c or 1

  • extend

Part 2. To shrink system partition in Server 2003

Different from DiskPart in Server 2008 and later Server OS, Windows Server 2003 does not offer “shrink” command in Diskpart service. To verify that, you can type “/?” in the DiskPart window and check all all available commands. From the screenshot, we can see there is no "shrink" command. So, DiskPart is unable to shrink a volume on the Windows Server 2003 computer.

Server 2003 Diskpart

Method 2. Try AOMEI Partition Assistant Server to resize Server 2003 partition

Although we can extend system partition in Server 2003 using DiskPart, not everyone has the same conditions: NTFS file system on C drive, enough unallocated space available at its right side and bootable disk. Plus, it cannot shrink any partition.

So, we need to turn to a third-party Server partition manager. The AOMEI Partition Assistant Server is a great choice to both extend and shrink system partition in Windows Server 2003, 2008 (R2), 2012 (R2), 2016 and 2019. Also, it supports expanding system drive on Windows 10/8/7 and Windows XP/Vista.

You can download the install the Demo Version of AOMEI Partition Assistant Server on your computer for a free trial.

Part 1. Extend Server 2003 system partition

To expand the system partition in Windows Server 2003, you can try its “Merge Partition” and “Allocate Free Space” features. Both methods can help you expand NTFS and FAT32 system partition when Windows Server is running (within Windows Server).

  • Merge unallocated space into system partition

The “Merge Partition” function can merge one, two or more parts of unallocated space into a partition. In addition, it is able to merge 2 adjacent partitions. If there is unallocated space on your disk, this method is recommended to extend the Server 2003 system drive.

Step 1. Launch and run AOMEI Partition Assistant Server. Right click the system partition and select “Merge Partitions” from the drop-down menu.

Merge Partition

Step 2. In this window, you will find the OS partition is chosen automatically, so you only need to tick another unallocated space and click “OK”.

Choose Unallocated Space

Step 3. Back to the main interface, click “Apply” and “Proceed” to commit the pending operation.

Apply Proceed

  • Allocate free space from other partition to Server system drive

The “Allocate Free Space” feature can directly assign some free space from one partition to another. More simple and convenient! If there is no unallocated space on the disk, it is a great solution.

Step 1. Right click the partition which has a lot of unused space left and select “Allocate Free Space”. Here we choose partition D:.

Allocate Free Space

Step 2. In the pop-out window, you can see how much free space this partition has. Now you can decide to assign how much of them to the target (system) partition.

Allocate Free Space From D To C Drive

Step 3. Then click “Apply” and "Proceed" to execute the pending operation.


Part 2. Shrink Server 2003 system drive

Above is how to extend system partition in Windows Server OS. If you want to shrink the system partition to make it smaller for some reasons, you can do as following:

Step 1. Right-click the OS partition and choose “Resize/Move Partition”.

Resize C Drive

Step 2. In the pop-out window, drag the slide bar leftwards to shrink C drive and click “OK”.


Step 3. Click “Apply” to execute the operation.


As you can see, AOMEI Partition Assistant Server makes it as easy as possible to resize system partition in Server 2003 no matter whether you want to extend or shrink it. Furthermore, it has many other amazing features including:

  • Clone Partition: copy a partition to another partition or hard disk for data transfer or backup.

  • Split Partition: split a large partition into two smaller partitions.

  • Quick Partition: quickly partition a large hard disk into several partitions within two clicks.

  • Align Partition: realize 4K alignment on both Hard Disk Drive (HDD) and Solid State Drive (SSD) to accelerate the reading and writing speed for your hard disk.

Final words

To resize system partition on Windows Server 2003, the native DiskPart can only work under some certain situations. By contrast, AOMEI Partition Assistant Server provides several easier and safer ways to extend disk partition easily. Besides, the AOMEI Partition Assistant Unlimited version allows unlimited usage within one company.