By Emily / Last Updated October 16, 2020

Windows Disk Management fails to work

When you need to format partition, delete partition, change drive letter, convert basic disk to dynamic, convert disk to MBR/GPT, and more in Windows 10, 8, 7, you are more likely to use Windows snap-in Disk Management. Press “Windows+R” to open "Run" dialogue. Then type "Diskmgmt.msc" and click "OK" to enter DM console. Right-click a partition or disk, and you can check all partition/disk functions. They allow you to perform some basic disk partition operations, but sometimes the offered features are not clickable.

Case 1. “Extend Volume” option greyed out

When there is no adjacent unallocated space right behind the aim partition you are going to extend, or the target partition is of FAT32 format, Disk Management won’t allow you to extend volume as usual. It can only extend NTFS or RAW partition followed by contiguous unallocated space.

Extend Or Shrink Greyed Out

Case 2. “Convert to MBR/GPT Disk” option is unclickable

When the selected disk contains volumes, you will be unable to convert it to MBR or GPT via Disk Management.

Convert To Mbr Disk Not Available

Case 3. “Delete Volume” option is disabled

If you are trying to delete partition on a removable media or delete EFI/OEM/recovery partition, you will find the “Delete Volume” greyed out.

The above are 3 typical and most-common situations where Disk Management fails to work. Of course, there are still some other cases in which DM cannot meet your requirements.

Powerful freeware partition manager download

If Windows Disk Management cannot satisfy your various needs, you can try the best free partition manager for Windows 10, 8, 7: AOMEI Partition Assistant Standard, which can make up the limitations of Disk Management and work much better. Click the below button to download the freeware partition manager and check out how it works. Here we take how to flexibly extend volume, convert disk between MBR and GPT, delete partition in Windows 10, 8, 7 as an example.

1. Extend Volume with non-adjacent unallocated space

As mentioned above, you can only extend NTFS and RAW volume when it is followed by an adjacent unallocated space in Disk Management. But, with the free partition manager, firstly, you can extend NTFS, FAT32, and RAW partition; secondly, you can extend partition with adjacent and non-adjacent unallocated space. If there is unallocated space but not right behind the target partition, try its “Merge Partitions” feature.

Step 1. Launch AOMEI Partition Assistant Standard. Right-click the partition you plan to expand and choose “Merge Partitions”.


Step 2. Tick the non-adjacent unallocated space and click “OK”.


Step 3. Click “Apply” to commit the pending operation.


If the available unallocated space is on the adjacent left side of the to-be-extended volume, you can use the “Resize Partition” function.
If there is no unallocated space, you can upgrade to Professional edition, whose “Allocate Free Space” can directly assign some free space from one partition to another.

2. Convert disk between MBR and GPT without deleting partitions

To convert a disk to MBR or GPT in Disk Management, you have to delete all partitions on it beforehand. Besides, it is able to only convert non-system disk since you are not allowed to remove system partitions within Windows. Luckily, AOMEI Partition Assistant Standard enables you to convert data disk to MBR/GPT without deleting existing partitions.

Step 1. Right-click the disk and choose “Convert to GPT disk” or “Convert to MBR disk”.

Convert Disk To Gpt

Step 2. Click “OK” to confirm your operation.

Gpt Ok

Step 3. Remember to click on “Apply” to commit the pending operation.

The free Standard edition only supports converting data disk. To convert system disk, use the AOMEI Partition Assistant Professional instead. It can convert boot disk within Windows as long as you can boot into it successfully. If Windows cannot start up for some reason, you can even create a bootable media via the software, and convert system disk without loading operating system.

3. Delete partition force

If you want to delete the partition on a USB flash drive, memory card or other removable media, or remove EFI/OEM/Recovery partition to free up disk space, but Disk Management does not allow you to do that, AOMEI Partition Assistant Standard is a great alternative.

Step 1. Right-click the partition (ex: Recovery partition) and select “Delete Partition”.

Delete Recovery Partition

Step 2. Choose a proper deletion method and click “OK”.

Delete Partition Quickly

Step 3. Click “Apply” to execute the pending operation.

If you want to delete or format C drive for fresh OS installation, you can first create a bootable media, and do that in WinPE environment.

Above are only 3 functions of AOMEI Partition Assistant Standard. Besides that, the freeware partition manager also provides the following amazing features that Disk Management :
>>Clone hard disk: copy all content from one disk to another and boot everything (OS, apps and programs) from the cloned disk successfully afterward.
>> Clone partition: clone just a partition from one disk to another partition or disk.
>>Migrate OS to SSD/HDD: move just OS partition to SSD or HDD without boot issues.
>>Wipe disk/partition/unallocated space: completely erase all data from the selected disk, partition or unallocated space.
>> Check bad sectors: check the partition for bad sectors and fix them.
>>Convert FAT32 to NTFS, or NTFS to FAT32 without data loss: change file system between FAT32 and NTFS without formatting or losing data.
>> Rebuild MBR: rebuild Master Boot Record, helping solve some common Windows boot failures.


So, with the free partition manager for Windows 10/8/7, you can manage your disk partition more easily and conveniently on Windows PC. If you are running Windows Server 2019/2016/2012 (R2)/2008 (R2)/2003, AOMEI Partition Assistant Server can satisfy your needs. To install the program on unlimited computers within one company/enterprise, try the Unlimited Edition, please.