Cannot extend C drive in Windows 7 – solution

Generally speaking, to use the hard disk space more efficiently, we create several partitions for different purpose, for example: C drive for Operating System, D drive for installed applications and others for data and backup. Nowadays, the applications become much larger and require higher CPU and more RAM, so we have to update the computer in several years. To improve computer performance, many people replaced traditional hard drive with Solid State Drive (SSD), because it is more stable and faster. However, the price of SSD is still much expensive, so few people will buy a large SSD, because it is just used for Operating System and applications.

Cannot extend C

The smaller hard disk, the higher risk of a drive to run out of space especially for system C drive. Windows 7 inherited Shrink Volume and Extend Volume functions from Windows Vista, which is able to resize partitions without losing data. However, many people get into trouble that they cannot extend C drive in Windows 7 after shrinking D, because Extend Volume is disabled.

In this article I’ll explain why you cannot extend C drive in Windows 7 after shrinking D, and give 1 step solution to solve this problem with free partition manager.

Why cannot extend partition in Windows 7

You may encounter this problem in several scenarios, but the reason could be concluded in one sentence: there is no adjacent Unallocated space. From Microsoft, to extend C drive or any data partition with Extend Volume function, there must be adjacent Unallocated space, in addition, the Unallocated space should be behind (on the right side). If you still do not understand, open your Windows 7 Disk Management and find out the corresponding scenario below.

Scenario 1:

Extend volume disabled

Explanation: you cannot extend C drive without Unallocated or free space.

Scenario 2:

Extend volume greyed out

Explanation: there is Unallocated space after shrinking D, but the Unallocated space is not behind C drive.

Scenario 3:

Extend volume disabled


Explanation: you cannot expand C drive even if you delete the adjacent volume D, because D is Logical partition. To convert the Free space to Unallocated space, you have to delete all Logical partitions as well as the entire Extended partition.

Note: if you do not understand what Logical and Extended partition is, simply search by Google.

What to do when you cannot extend volume in Windows 7

If you have already shrank D or other adjacent volume to get Unallocated space, you just need 1 step to move the Unallocated space to behind C drive with free partition software such as NIUBI Partition Editor Free, step:

DownloadNIUBI Partition Editor Free and you’ll see the disk partition properties as well as the available functionalities.

NIUBI Partition Editor

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

Move volume

The 10GB Unallocated space will be moved to behind C drive.

Unallocated moved

Now, you can extend C drive with Window 7 Disk Management or this free partition manager.

If you have not shrank D, there is easier way to extend volume in Windows 7, watch the video:


NIUBI Partition Editor Free Edition is 100% free and clean partition manager software for Windows 10/8/7/Vista/XP (32 & 64 bit). It is able to create, delete, format, copy, convert, defrag, check, scan, wipe, resize, move, shrink, extend, hide partition and much more. You can resize volume safely to optimize disk space usage and manage disk partitions much easier. Learn More

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