How to increase C drive space in Windows Server 2008 R2

by Andy, Updated on: September 12, 2022

What will you do when system C drive is getting full on Windows 2008 server? If you contact server OEM manufacturers, they'll tell you to back up everything, recreate partitions and restore. It sounds reasonable, but if you do like that, your whole happy weekend will be wasted. The worst, server is offline during this period. To solve this problem faster and easier, you can extend C drive with free space in other partitions. This article introduces 3 ways to increase C: drive space in Windows Server 2008 R2 without losing data.

1. Increase C drive space in Server 2008 R2 without software

Windows Server 2008 (R2) has native Diskpart command and GUI Disk Management tools, both have the ability to decrease and increase partition size. However, they only work under specific condition: before extending C: drive you must delete the contiguous partition on the right.

Although both native tools can decrease partition, they  cannot expand C drive by shrinking other partitions. As you see in my server, Extend Volume is disabled for C and E drive after shrinking D. This is because:

  • Windows native tools can only make Unallocated space on the right while shrinking a partition.
  • Unallocated space can only be merged into the left contiguous partition with either native tool.

If there is no contiguous partition on the right or you cannot delete it, you cannot increase C drive space in Server 2008 r2 with either native tool.

If you want to extend C drive for Server 2008 without any software, the right contiguous partition must be Primary even if you can delete this partition.

Extend greyed out

2. Extend C drive in Server 2008 r2 with free space in D/E

To increase C: drive space in Server 2008 R2, the better choice is running server partitioning software such as NIUBI Partition Editor. You don't have to delete partition, because Unallocated space can be made on either left or right side. If you want to transfer free space from any nonadjacent partition (such as E:), Unallocated space can be moved to behind C drive. To accomplish these tasks, you just need to drag and drop on the disk map.

Download NIUBI Partition Editor, you'll see all disk partitions with structure and other information on the right, available operations to selected disk or partition are listed on the left and by right clicking.

In my test server, there is drive C, D, E and a system reserved partition on Disk 0, original size of partition C is 40GB.

NIUBI Partition Editor

How to increase C: drive space in Server 2008 R2 with NIUBI Partition Editor:

Step 1: Right click drive D: and select "Resize/Move Volume", drag left border towards right in the pop-up window, or enter an amount in the box behind "Unallocated space before" (1024MB = 1GB).

Shrink D

Then part of unused space is converted to Unallocated on the left.

Shrink D

Step 2: Right click C: drive and select "Resize/Move Volume", drag right border towards right in the pop-up window..

Extend C drive

Then the free Unallocated space is added into C drive.

Extend os drive

Step 3: Click Apply on top left to take effect.

As long as there's free space in other partition on the same disk, NIUBI Partition Editor can transfer into C drive, no matter these partitions are adjacent or not. Watch the video how to increase C: drive free space in Windows 2008 server from other volumes:

Video guide

  • In my server Drive D is the right contiguous partition, E is a non-adjacent partition, the drive letters may be different on your own server.
  • If you use any types of hardware RAID arrays such as RAID 1/5/6/10, do not break array or do any operations on the controller, simply follow the steps above.
  • If you run Windows Server 2008 as virtual machine in VMware, Hyper-V or VirtualBox, simply install NIUBI to the virtual server and follow the steps above.

3. Enlarge C drive in Windows Server 2008 with a disk

If there is no available free space in all partitions on the same disk, the method above is invalid. No software can enlarge C drive by adding free space from other separate disk. However, you can clone system disk to a larger one and extend C drive with additional disk space.

The separated disk means Disk 0, 1 (or other) that are shown by NIUBI or Windows Disk Management.

Follow the steps in the video to increase C drive size in Windows Server 2008 (R2) with another disk:

Video guide

If there are several partitions on this disk, another method is moving one of the partitions to another disk, then delete this partition and add its space to C drive.

Increase C drive space in Server 2008 R2 VMware/Hyper-V

To decrease data partition and increase C drive space in Windows Server 2008 R2, you need 3rd party software in most cases. To ensure Operating System and data safety, you'd better back up and select a reliable tool. Otherwise, there is risk of system damage and data loss. As the safest tool, NIUBI Partition Editor has powerful technologies to protect your system and data.

In addition, it is 30% to 300% faster than other tools because of the advanced file-moving algorithm. This is very useful to save time especially when there are large amount of files in the partition that you want to shrink and move.

Besides resizing partitions to increase C drive space in Windows Server 2008/2012/2016/2019/2022, NIUBI Partition Editor helps you copy, convert, defrag, wipe, create, delete, format partition, scan bad sectors and much more.