Step 1. Locate the Target Partition.
Go to Partition Manager, locate the target partition and select “Resize/Move”.

Step 2. Extend the Target Partition.
Drag the partition panel rightward or leftward to add the unallocated space into your current partition and click “OK” to confirm.

Extra Option: Get Space from Another Drive
If there is not enough unallocated space on your disk, right-click on a big partition with enough free space, select “Allocate space”.
Then select the target partition that you want to extend at the allocate space to column.

Step 3. Execute Operations to Extend Partition.
Drag the dots of the target partition into the unallocated space and click “OK”.

Then Click the “Execute Task” button and click “Apply” to keep all the changes.
Except for resizing partition, EaseUS Partition Master provides more one-stop disk partition features. For example, you can clone disk, merge adjacent and non-adjacent partitions, create/delete/format partition, wipe data, and convert disk/partition conversion (e.g., convert MBR to GPT).
2. Extend C Drive Space in Disk Management by Deleting Partition
Disk Management comes with Windows and has many functions to manage disks, including extend volume, shrink volume, format partition, delete partition, etc.. You can use the “Extend Volume” option for increasing C drive space if you don’t want to use the third-party EaseUS Partition Master to extend C drive.
Yet, there is a condition when extending C drive via Disk Management; that is, there needs to be some unallocated space very behind the C drive. Otherwise, the extend volume will be greyed out.
If there is no unallocated space, how to increase the space in C drive? We should first create unallocated space by deleting partitions and make sure it locates right behind C drive. Then, extend C drive with the unallocated space. Do it by following the guides below.
Next, we will show an example of how to increase C drive space by removing D drive, which is very behind C.
Step 1. Open Disk Management, right-click partition D, and choose “Delete Volume”. When the process finishes, we can see there is unallocated space and locates right behind C drive.

Step 2.Now, right-click on C drive and select “Extend Volume”. Extend Volume Wizard will pop up. Follow the on-screen guide to complete increasing C drive.

3. Increase Space in C Drive Using Command Prompt
If you are a computer expert, you can use the command lines to extend C drive. Otherwise, be careful to run these commands to make sure you can move more space to C drive without any extra issue, or use the automatic EaseUS partition manager to help you out.
If there is an adjacent unallocated space behind the system C drive, you can follow the steps below:
Step 1. Type diskpart in the Search Bar and hit enter.
Step 2. Input these commands orderly, and press Enter after each command line.
list disk
select disk n (n is the disk letter of your system hard disk)
list partition
select partition n (n is the drive letter of the system drive)
extend
exit
If there is no unallocated space right behind the system C: drive, follow the below steps:
Step 1. Type diskpart in the Search Bar and hit enter.
Step 2. Input the following commands one by one and press Enter after each command line.
list disk
select disk n
list partition
select partition n (n is the drive letter of the partition behind C drive)
delete partition
select partition m(m is the drive letter of system partition)
extend
exit
How to Increase C Drive Space Summary
This page covers all the effective solutions to increase C drive space in Windows 10/8/7. To optimize your hard disk and partition to enhance computer performance, we highly recommend you equip your computer with EaseUS Partition Master.
With this partition management tool, you can take full advantage of your disk space without effort by resizing, merging, creating, formatting, deleting, cloning, migrating, and converting partitions.