Like in previous versions of Windows operating system, the Disk Management tool in Windows 10 enables you create, format, delete, shrink and extend partitions without the help of third-party software.
In one of our previous guides titled how to extend a partition in Windows 10, we discussed about extending the system partition using Disk Management tool as well as third-party utility.
While trying to extend system or any other partition using the built-in Disk Management utility, you might see that the Extend Volume option, which appears when you right-click on a partition, is grayed out or disabled. In short, the Disk Management might not allow you extend a partition even if you have unallocated space on the drive.
If the Extend volume option is not clickable or grayed out, it could be because of one of the following reasons.
Reason 1 of 4
You are trying to extend FAT or FAT32 partition
Yes, the Extend volume feature is applicable only to the NTFS partitions. In other words, Windows doesn’t support extending FAT and FAT32 file systems out of the box. If you want to extend FAT or FAT32 partition, you need to use third-party tools like MiniTool Partition Wizard free edition.
Here is how to check if a partition is formatted with FAT, FAT32 or NTFS:
Step 1: Open This PC. Right-click on the drive that you want to check, and then click Properties.
Step 2: Under the General tab, you can see the current file system next to File System. In the picture, the drive is formatted with NTFS.
If you want to extend a FAT or FAT32 partition, either use MiniTool Partition Wizard free software or convert FAT/FAT32 to NTFS first.
Reason 2 of 4
There is no unallocated space on the drive
Many of you might aware of this but most users are not aware of the fact that there must be unallocated or unpartitioned space on the drive in order to use the Extend volume feature. Just because there is GBs of free space on one of your partitions, you can’t extend a volume using free space available on another partition.
If you have free space on one partition, you need to shrink the partition first to create some unallocated space and then use the Extend volume feature.
Reason 3 of 4
The unallocated space is not to the right of the partition that you want to extend
At times, even if you have GBs of unallocated space on the drive, Windows 10 won’t display the Extend volume option as the unallocated space is not after the partition that you want to extend. The unallocated space must immediately follow the volume or partition that you want to extend.
Let’s say that the unallocated space is after “C” drive and before the “D” drive. So, in this case, the unallocated space is after “C” drive and there is no unallocated space immediately after “D” drive. Because of this, when I right-click on “C” drive/partition, Windows displays Extend volume option. The same option is grayed out when I right-click on “D” drive because the unallocated space is not immediately after the “D” drive. In the picture below, the unallocated space is to the right of the partition “C”, and Windows allows me to extend “C” drive without any issues.
Once again, in this situation, we recommend using the excellent MiniTool Partition Wizard free edition to extend your partition without any issues.
Reason 4 of 4
The unallocated space is not in the extended partition
If you’re trying to extend a logical drive on a basic disk, please remember that the unallocated free space must be in the extended partition that immediately follows the logical drive.
In simple words, if you’re unable to extend a volume or partition using Disk Management, please use the MiniTool Partition Wizard free edition. If your PC is unbootable, create MiniTool Partition Wizard bootable USB, boot from the USB, and then extend the partition.