Three Methods to Fix Disk Management Can’t Extend Boot Partition in Windows 7/10

July 18, 2017

Why you cannot extend system drive (boot partition) even if there is unallocated space on the same hard drive? How do you solve this issue on earth? Following gives answers.

The Scenario

Hello, all. This question bothers me for a long time. So please help me figure it out. Here is the case: I have 80 GB in system boot partition C which becomes red in Explorer a few weeks ago. I’ve received “low disk space” warning several times. When I go to Disk Management of Windows 7, I found that I have some unallocated space at the end of the disk. I guess I could extend the C drive with that unallocated space. However, when right click my boot partition, only to find that the “Extend Volume” is grayed out. How come? I was told to delete partitions in the middle of the disk to complete extending. This is horrible since I’ve installed many applications in D drive. Why can’t Windows just see the unallocated space and move it to my C drive?

Above situation may not unfamiliar to most Windows users. There are many cases that need to extend system partition. Nevertheless, issues like “Disk Management can’t extend boot partition” always prevent us from managing computer better. What are the exact factors that affect our operations?

Why Can’t Extend Boot Partition in Windows 7/10?

As a matter of fact, reasons could be very simple. When you can’t extend partition in Windows 10 or Windows 7, two main reasons are account for Windows 7 or Windows 10 Extend Volume grayed out:

  • The unallocated space is not adjacent to the boot partition you want to extend. This is the same reason for the trouble in the example. You can only extend the boot partition into contiguous unallocated disk space.

  • There is no unallocated space on the same physical hard drive. Some users have two or more hard drives installed. But it is impossible to add unallocated space of this physical basic disk to a partition on that physical basic disk.

In Windows XP or the previous, you are likely to encounter “can’t extend C drive with unallocated space” trouble because there is no an option named “Extend Volume” in Disk Management. “Extend Volume” and “Shrink Volume” are new features come with Windows 7 and later. Yet it supports to resize partition using Diskpart. The first case can be solved by using following methods, but the second one requires hard drive RAID or dynamic disk. 

By the way, there is another situation that you cannot extend partition in Windows. If you have unallocated space on your USB drive, SD card or the like, when right click the first partition in Disk Management, the “Extend Volume” is also grayed out. Windows only recognize the first partition on a removable device, so even if you have more than one partition on the device, that option is invalid. 

How to Fix Windows 7 Can't Extend Boot Partition?

Can you extend a boot partition? Of course! Now that Windows Disk Management cannot help you in extending system boot partition, it is time to seek help from third-party software. Many free partition mangers on the market can solve this trouble, and AOMEI Partition Assistant Standard is one of them. This disk partition software allows you to resize partition, move partition, delete partition, etc. With the help of this partition tool, you can solve aforementioned issue like a breeze. Windows 10, 8.1/8, 7, XP, and Vista are supported. Download it to have a try. Install and run this software. You have three methods in total to choose.

Note: Please backup files that you care most in case of data loss under inappropriate operations.

Method 1: Extend Boot Partition by Moving Unallocated Space

1. Right click the partition next to the unallocated space and select “Move Partition”.

Move Partition

2. In the pop-up window, drag this partition to the right side.

move to the right side

3. You'll find the unallocated space is before this partition. Click “Apply” > “Proceed” to execute it.

Apply

4. Repeat above steps until the unallocated space is adjacent to the boot partition.

Method 2: Extend Boot Partition by Merging Unallocated Space

1. Right click the boot partition (C drive in general) and select “Merge Partition”.

Merge Partitions

2. In the pop-up window, check C drive and the unallocated space and then click “OK”.

Merge Unallocated Space

3. Click “Apply” > “Proceed”.

Method 3: Extend Boot Partition by Allocating Free Space from Existing Partitions 

If there is no unallocated space on the same hard drive, this method will do you a big favor. It will allocate free space from other redundant partitions to the boot partition directly. The whole process can be completed in one step. Before you start, please upgrade Standard to Professional edition.

1. Right click the redundant partition and select “Allocate Free Space”.

Allocate Free Space

2. In the pop-up window, specify the size of free space and choose the boot partition as the target partition.

Specify Free Space

3. Click “Apply” > “Proceed”.

AOMEI Partition Assistant Professional has many other useful features in computing. For example, you can migrate OS from GPT disk to GPT/MBR SSD or HDD; Convert system/boot disk between MBR and GPT styles; Convert Dynamic disk to basic and vice versa; and manage disk partition from Command Prompt.

Conclusion

Next time when you face “Disk Management can't extend boot partition” or similar troubles, I am sure you'll fix it confidently. In Disk Management, you may want to convert FAT32 to NTFS without formatting, which could be done using AOMEI Partition Assistant as well.