How to Extend Partition Size on Windows 10

 

Solution 1: Extend C Drive Windows 10 via Disk Management

There must be unallocated space behind the partition which you want to expand with Windows built-in Disk Management utility. Otherwise, you might find that the Extend Volume option is greyed out and not available.

Step 1. Right-click My Computer and choose "Manage -> Storage -> Disk Management".

Step 2. Right-click on the partition that you want to extend, and choose "Extend Volume" to continue.

Step 3. Set and add more size to your target partition and click "Next" to continue.

 

Step 4. Click "Finish" to complete the process.

Solution 2. Extend C Drive Windows 10 via CMD

There is another tool named Diskpart which also enables you to manage your disk and partition. The Windows Command Prompt works the same as Disk Management. One important point is that inexperienced users should not rush to this method because a tiny mistake is able to do damage to the entire hard drive. 

Step 1. Press Windows + X keys and choose "Command Prompt (Admin)".

Step 2. Type the following commands and each one ends with "Enter" key:

diskpart

list volume

select volume x 

extend size =number

In my case, the system C drive is Volume 1. If there is no unallocated space, you can't extend C drive in Windows 10 with this method.

Extend C drive or system partition in Windows 10Extend C drive or system partition in Windows 10