Unable to extend C drive

Solution – cannot extend C drive in Windows 7 Disk Management

Many people feedback that they can’t extend C drive in Windows 7 Disk Management. After shrinking drive D, Extend Volume is disabled for C drive, so they cannot extend C drive with the build-in feature. In this article, I’ll explain why you unable to extend C drive with Extend Volume and how to solve this problem with ease.

Why you unable to extend C drive

From Microsoft explanation, both Shrink Volume and Extend Volume features of Disk Management only support NTFS partition. However, few computers use FAT32 partition for system C drive, so this is not an issue. There are 2 common reasons why you can’t extend C drive in Windows 7 Disk Management:

  1. No adjacent Unallocated space behind C
  2. Free space in Extended partition cannot be extended to Primary partition

1. No adjacent Unallocated space behind C

A 160GB hard disk cannot be increased to 250GB itself, so before extending a drive you must shrink another one. If you right click C drive directly without shrinking other disk partition, of course Extend Volume is greyed out.

Extend Volume disabled

From Microsoft, Extend Volume only works when there is adjacent Unallocated space on the right side of the drive that you want to extend. This is the reason why many people feedback that they cannot extend C drive in Windows 7 Disk Management.

In my Windows 7 laptop, the 20GB Unallocated space is shrank from drive D. As you see, it is on the right side of D, so you unable to extend C drive except that you can move this Unallocated space to the left side of D drive.

Cannot extend C drive

2. Free space in Extended partition cannot be extended to Primary partition

Different with Windows 10 that formats disk as GPT by default, Windows 7 format the hard disk as MBR, so there is potential issue if you use the default MBR disk. In MBR style disk, there could be maximum 4 partitions if you create them all as Primary partition. To use more drives, you can only create 1 to 3 Primary partitions plus an Extended partition. In this Extended partition, you can create many Logical partitions. It is bothersome, right? But it’s true.

Shrinking drive D cannot get adjacent Unallocated space behind C drive, so some people try to delete drive D.

Delete D

Different with Primary partition that converts to Unallocated space after deleting, Logical partition converts to Free space. In this situation, you can’t extend C drive in Disk Management even if you delete drive D.

Free space

Then what to do? If you insist on extending C drive with Disk Management, the only option is by deleting all Logical partitions as well as the entire Extended Partition.

Delete Extended partition

Then Extend Volume is enabled for C drive.

Extend Volume enabled

Note: do not delete drive D even if it is Primary partition, otherwise, all installed programs will be deleted, too.

Then what is the best way to solve this problem?

Solution when you can’t extend C drive

When you unable to extend C drive in Windows 7 Disk Management, run NIUBI Partition Editor, as the safest and fastest Windows partition software, it helps you fix this issue safely and easily. NIUBI Partition Editor can shrink drive D and generate Unallocated space on the left side. If you have have shrank D in Disk Management, NIUBI can move the Unallocated space to behind C drive. Better than Disk Management, NIUBI can shrink and extend both NTFS and FAT32 partitions.

Move Unallocated space to behind C drive

Download NIUBI Partition Editor, as you see, there is an 20GB Unallocated space that is shrank from drive D in my Windows 7 laptop.

NIUBI Professional

Right click drive D and select Resize/Move Volume, drag the middle position rightwards in the pop-up window.

Move partition D

Unallocated space is moved to the left side of drive D. (Note: disk partition won’t be changed until you click Apply on top left to confirm.)

Partition D moved

When you right click C drive in Disk Management, Extend Volume is activated.

Extend Volume activated

You may extend C drive with either Disk Management or NIUBI Partition Editor, NIUBI is much easier.

Right click C drive and select “Resize/Move Volume” again, drag the right border rightwards in the pop-up window to combine the Unallocated space.

Extend C drive

C drive space is extended to 50GB.

Merge Unallocated to C

Shrink data volumes

If you have not shrank drive D in Disk Management, NIUBI can generate Unallocated space on the left side directly without moving Unallocated space.

Partition Editor

Right click drive D and select Resize/Move Volume, drag the left border rightwards in the pop-up window.

Decrease D

Unallocated space is generated on the left side of D, you just need to right click C drive and combine the Unallocated space with Resize/Move Volume feature.

Unallocated produced

When you cannot extend C drive in Windows 7 Disk Management, run NIUBI Partition Editor to move Unallocated space to behind C drive, or shrink drive D to get adjacent Unallocated space. To extend C drive, simply run Resize/Move Volume feature to combine the Unallocated space.

Download to try

What to do when you can’t/unable to extend c drive in Windows 7?
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