“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 , 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?”
The above situation may not be unfamiliar to most Windows users. There are many cases that need to extend boot partition Windows 10. 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 10, 8, 7?
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 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 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 recognizes the first partition on a removable device, so even if you have more than one partition on the device, that option is invalid.
Solved: Windows 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 partition managers on the market can solve this trouble, and AOMEI Partition Assistant Professional 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 the aforementioned issue like a breeze. Windows 10, 8.1/8, 7, XP, and Vista are supported. Install and run this software. You have three methods in total to choose.
Method 1: Extend Boot Partition by Moving Unallocated Space
1. Right-click the partition next to the unallocated space and then select “Resize/Move Partition”.
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 the 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 choose the “Resize/Move Partition” option.
2. In the pop-up window, check C drive and the unallocated space and then click “OK”.
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.
1. Right-click the partition which has redundant space, and then click “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 to convert FAT32 to NTFS without formatting, which could be done using AOMEI Partition Assistant as well.