“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
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
2. In the pop-up window, drag this partition to the right side.
3. You'll find the unallocated space is before this partition. Click “Apply” >“Proceed” to execute it.
4. Repeat above steps until the unallocated space is adjacent to the boot
Method 2: Extend Boot Partition by Merging Unallocated Space
1. Right click the boot partition (C drive in general) and select “Merge
2. In the pop-up window, check C drive and the unallocated space and then click
3. Click “Apply” > “Proceed”.
Method 3: Extend Boot Partition by Allocating Free Space from Existing
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
1. Right click the redundant partition and select “Allocate Free Space”.
2. In the pop-up window, specify the size of free space and choose the boot partition
as the target partition.
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.
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
FAT32 to NTFS without formatting, which could be done using AOMEI Partition
Assistant as well.