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Warning: C drive becomes red
During the usage of a computer, applications keep being installed into Windows
system. One day, you may get mad at your computer because you have to wait for extra
time when you try to launch an application or close it. It is absolutely annoying!
And when you open “Computer”, you’ll find that C drive becomes red.

It is a warning that you are running out of disk space on C drive. You are supposed
to delete old and unnecessary files in order to make more free space. However, it
proves useless when the problem comes again after a short period of time. Now you
must be searching for a more effective way—increasing memory of C drive. If you
don’t know how to increase disk space in C drive safely, move on to the next
part.
How to increase memory of C drive effortlessly in Windows 7/8/10?
To optimize computer performance by increasing memory of C drive, there are three
effective methods at hand.
Method 1: increase memory of C drive using Disk Management
As Disk Management is familiar to most computer users, what comes to you first is how
to extend C drive using Disk Management. Follow the steps below:
1. Right-click the “Computer” icon on the desktop and hit the “Manage”
option.
2. Click on “Disk Management” to open Windows Disk Management.
3. Select C drive, right-click and hit “Extend Volume”.

4. Set the amount of space to be extended to C drive following Extend Volume Wizard.

Tip: The “Extend Volume” option can be greyed out if there is no
contiguous unallocated space on the right side of C drive. On that occasion, if
there are other partitions on the same disk, you can choose to delete the adjacent
partition to create
unallocated space but you must make sure your crucial data have been backed
up before that. The process might be time-consuming and error-prone.
Method 2: increase memory of C drive with Diskpart
Some people prefer to increase C drive space with Diskpart. Then, do following
steps:
1. Press Windows Key + R to open the Run dialogue.
Type diskpart and click “OK”.
2. Type list volume and press Enter.
3. Type select volume # (ex: Volume 1) to select C drive that
you want to extend and press Enter.
4. Type extend size=# (ex: size=2048) to extend C drive by size in
megabytes (MB) and press Enter.
5. Type exit and press Enter to exit Diskpart.

Tips:
● You may fail to extend C drive if there is no contiguous unallocated space on
the disk.
● If you do not specify a size, C drive will be extended to take up all the
contiguous unallocated space.
Method 3: increase memory of C drive via a handy software
Now you see the limitation of extending C drive with Disk Management and Diskpart.
Here comes a handy partition manager— AOMEI Partition Assistant Professional.
It helps you increase memory of C drive as long as there is unallocated space on the
same disk, whether it’s right behind C drive or not. I’ll tell you how to increase C
drive space in Windows 7 without formatting via AOMEI Partition Assistant in detail.
It also applies to other Windows operating systems, like Windows 8/10, etc.
Step 1. Launch AOMEI Partition Assistant. Right click C drive,
select “Merge Partitions”.

Step 2. Find unallocated space, tick in the box and click “OK”.

Step 3. Confirm “Pending Operations” and click “Apply” to
execute the operation.

Tip: You can see clearly from Step 1 that the unallocated space
lies behind D drive instead of C drive. By “Merge Partitions” option, the
unallocated space will be moved and added to C drive automatically.
▶ Increase memory of C drive via Command Prompt
1. You can also use AOMEI Partition Assistant command lines to extend C drive. Just
input following command lines and press Enter after each:
cd C:\Program Files (x86)\AOMEI Partition Assistant Pro Edition
7.0 (You should change the path after “cd” with the installation
directory of AOMEI Partition Assistant on your computer.)
partassist.exe /list

partassist.exe /resize:C /extend:1024 (By default, the specified
size is in MB, and GB is also available.)

2. For the target partition is system partition, the operation will be completed
under AOMEI Partition Assistant PreOS Mode. Wait for the process to be completed and
restart your computer after that.

Summary
If you find your computer works slower and slower, try to increase memory of C drive
via three methods mentioned above. However, AOMEI Partition Assistant is a powerful
partition manager with more practical features. It can also help you move partitions, allocate free space from
one partition to another and so on.