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Windows Server 2003 Extend C Drive: Two Ways to Extend System Partition

How to extend system partition on Windows Server 2003? Here we will guide you to extend the C drive on Windows Server 2003 with the Diskpart command and EaseUS Partition Master Server Edition. Both are simple and easy solutions to Windows Server 2003 extended C drive.

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Updated by Daisy on Feb 22, 2023
Written by Jean

Applies to extend C drive Windows Server 2003, 2008 (R2), 2012 (R2), 2011, 2016, and 2019, as well as Windows 10/8/7/XP/Vista. Though earlier Windows Server 2000, Windows NT before 2003 is rare to see nowadays, the solutions to extend system partition work on those operating systems, too.

How to Solve Windows Server 2003 Extend C Drive

Windows Server 2003, 2003 R2, 2008, 2008 R2, 2012, 2012 R2...to the latest 2019 is recognized as an enterprise-level operating system with enhanced management solutions and robust hardware and software configurations. To ensure an enduringly stable performance of the involved highly configurable servers/computers, do not let your system partition run out of space. Otherwise, it will lag behind in boot time, loading large files, running applications, networking and so forth. Nonetheless, with regular disk cleanup, administrators still cannot escape from seeing "low disk space" on the system C partition. 

How to extend system partition on Windows Server 2003? Here we will guide you to extend C drive on Windows Server 2003 with EaseUS Partition Master Server Edition and Diskpart command. 

Workable Solutions Step-by-step Troubleshooting
#1. (Safe Method) Using EaseUS Partition Master in Windows Server 2003 Extend C Drive Resize/Move partitions; Merge partitions; Allocation Space...Full steps
#2. Utilizing Diskpart for Windows 2003 Extend C Drive Solve common errors and extend C drive...Full steps

EaseUS Partition Master is a famous third-party personal OS and Server partition manager software, with three overwhelmed options to extend the C drive space without data loss. While Windows also has a built-in Windows disk management solution, Diskpart.exe, but it requires unallocated space which comes from shrinking or deleting an existing partition drive. If you are not familiar with Diskpart.

#1. (Safe Method) Using EaseUS Partition Master in Windows Server 2003 Extend C Drive

To extend system partition on Windows Server 2003, we recommend you to use EaseUS Partition Master Server Edition. It is the leading server partition software to partition server disk for IT administrators. It manages Windows server hard drives quickly and safely.

You may perform basic and advanced partition operations on your Server without data loss, including: Resize and Move partitions, Copy Partition, Copy Disk, Copy Dynamic Volume, Create and Delete partitions, Format partitions, Convert partitions, Split partition, Merge partitions, Explore partitions, Hide and Unhide partitions, Set active partition, etc. Changes of server partition can be previewed before applying to hard disk, and all data is completely protected during any operation.

EaseUS Partition Master Enterprise


Your trustworthy Windows Server disk manager.

Extend System drive, combine/split partitions.
Clone disk, migrate OS to HDD/SSD.
Convert MBR to GPT, GPT to MBR, no data loss.
1-click adjust disk layout, create volumes at one time.

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The most noticeable feature of extending system partition on Windows Server 2003 by EaseUS Partition Master Server Edition is no data loss, plus the operation interface is much viewable. You got three options to undertake the process of increasing space in system C drive partition, which both ensure zero data loss.

Though safer than the Diskpart command, we still suggest you back up the server when you decide to extend system partition on Windows Server 2003 in case of unexpected shutdown or any other hardware failure.

Option 1. Resize/move partition without losing data

Step 1. Locate the Target Partition.

Go to Partition Manager, locate the target partition and select "Resize/Move".

Select target partition to extend

Step 2. Extend the Target Partition.

Drag the partition panel rightward or leftward to add the unallocated space into your current partition and click "OK" to confirm.

choose another drive to allocate space

Extra Option: Get Space from Another Drive

If there is not enough unallocated space on your disk, right-click on a big partition with enough free space, select "Allocate space".

Then select the target partition that you want to extend at the allocate space to column.

choose another drive to allocate space

Step 3. Execute Operations to Extend Partition.

Drag the dots of the target partition into the unallocated space and click "OK".

finish extending partition

Then Click the "Execute Task" button and click "Apply" to keep all the changes. 

Option 2. Merge C drive with D drive without losing data

Step 1: Select the target partition

Right-click on the partition which you want to add space to and keep, and select "Merge".

Run EaseUS partition manager software

Step 2: Select a neighbor partition to merge

Select one partition next to the former selected partition to merge.

Select partitions to merge

And click "OK" to continue.

Confirm merge partitions

Step 3: Execute operation to merge partitions

1. Click the "Execute Task" button at the top and then click "Apply".
2. The program will merge space and add files from the second partition to the first partition.

Select partitions to merge

Option 3. Allocate space to C Drive without losing data

Step 1. Right-click on the D: partition with enough free space and select "Allocate Space".

Select partition to allocate space

Step 2. Select the target partition - C: drive and drag the partition panel rightward to add the free space from D: drive to C: drive. Then click "OK" to confirm.

Allocate space to extend partition

Step 3. Click the "Execute Task" button and click "Apply" to start the process of moving free space from D: drive to C: drive.

finish extending partition

Video Tutorial about how the EaseUS Partition Master works:

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#2. Utilizing Diskpart for Windows 2003 Extend C Drive

To extend C drive on Windows Server 2003 with Diskpart commands, there must be a continuous unallocated space next to the C drive. This is the precondition that enables you to utilize the Diskpart command to take effect. Otherwise, you'll receive an error message that prevents you from executing the next command.

Error: The volume you have selected may not be extended

The volume you have selected may not be extended.
Please select another volume and try again.

windows server 2003 extend partition error

The reason behind the error message is concerned with the precondition as we've explained. It's due to the lack of unallocated space. In addition, the system volume can only be extended by running Diskpart.exe from a command line by a bootable CD.

unallocated space behind C drive

How to solve common errors and extend C drive in Diskpart

Step 1. Open Diskpart Command Prompt in Windows Server 2003

Input Diskpart in the search bar, and click "OK" to enter the Diskpart Utility.

Step 2. Extend C drive with continuous unallocated space

"x" in the examples refers to the number of a hard disk or partition.

  • Input list disk command, and press Enter. Then, all of the disks will be listed.
  • Input select disk x command to select the target disk, and then press Enter.
  • Input list partition and press Enter. Then, all the partitions will be listed.
  • Select the number of system partition that needs to be extended by inputting select partition x and pressing Enter.
  • Input Extend command, and press Enter.
  • Input Exit to leave the Diskpart window.

Step 3. Extend C drive with non-continuous unallocated space (Data backup is required)

When there is no unallocated space right behind system volume, you have to delete the adjacent drive to get unallocated space and then increase the C drive by inputting the relevant commands followed by the Enter key.

"x" in the examples refers to the number of a hard disk or partition.

  • list disk
  • select disk x
  • list partition
  • select partition y
  • delete partition
  • select partition x
  • extend
  • exit

Bonus Tip: Extend Server System Partition with Disk Management

This video includes a bonus way that you can follow, which is to extend the system partition on Server computers with Disk Management. Check this out:

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About the Author

Updated by Daisy

Daisy is the Senior editor of the writing team for EaseUS. She has been working in EaseUS for over ten years, starting from a technical writer to a team leader of the content group. As a professional author for over 10 years, she writes a lot to help people overcome their tech troubles.

Read full bio

Written by Jean

Since graduating from university, Jean has been writing tech articles and has been a valuable member of the EaseUS team for over 5 years. Her areas of expertise include data recovery, disk partitioning, data backup, and multimedia world.

Read full bio

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  • I love that the changes you make with EaseUS Partition Master Free aren't immediately applied to the disks. It makes it way easier to play out what will happen after you've made all the changes. I also think the overall look and feel of EaseUS Partition Master Free makes whatever you're doing with your computer's partitions easy.

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  • Partition Master Free can Resize, Move, Merge, Migrate, and Copy disks or partitions; convert to local, change label, defragment, check and explore partition; and much more. A premium upgrade adds free tech support and the ability to resize dynamic volumes.

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  • It won't hot image your drives or align them, but since it's coupled with a partition manager, it allows you do perform many tasks at once, instead of just cloning drives. You can move partitions around, resize them, defragment, and more, along with the other tools you'd expect from a cloning tool.

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