Why do you need to resize partition?
Resizing partition means to change the size of a partition as you like, either
extend it or shrink it. But when you shrink a partition, you can at most shrink it
to the size of its used space so that you can use the partitions with more
flexibility. For example, you can store applications or files on any one of the
partitions. If the partition is running out of space, you can extend it with the
space shrunk from other partitions. Besides, you can create new partition with the
room get from other partitions.
Here are several situations in which you would like to resize partition:
When you buy a new laptop or PC, it may have been pre-installed with a system and
come with a big C drive but small data partitions, or a small C drive but large data
partitions. No matter which one it is, you will find it cannot make full use of disk
When the computer has been used for a long time, you may have encountered the
message: the system drive is running out of space.
If Windows 10 upgrade failed with error “Couldn’t update system reserved
partition”, the most likely cause is the system resvered partition is too small.
Then you can extend system reserved partition.
For example, once when I was downloading a player online, following the installation
steps without setting the destination, a message came saying that my c disk has not
enough space to install the application. Thus, I have to either reset the
destination or give up my intention. Therefore, later, I was used to set d or f
partition as the destination to avoid such problem following the advice of my
I know I can extend my c drive with Windows self-contained function but I didn’t know
how for it seems very difficult. Being neither a computer professional nor a
computer lover, I’m usually been caught by problems. It is extremely annoying! But
now, I’m not troubled by such problems anymore with AOMEI Partition Assistant Professional. It
helps me manage my disks very well with its intuitive interface and simple steps. By
the way, it is compatible with Windows 10, Windows 8/8.1, and Windows 7.
Before you do
Check the partitions you want to resize and make sure there is no error.
Do not forcibly terminate the tasks or cut off the power or you might lose your
Close all running applications on the partitions you want to resize.
Resize partition with Partition Assistant
Case 1: Extend Partition
To extend partition means increase partition size; you should notice two points
There must be an unallocated space locating on the same hard disk as the partition
you want to extend. If there's no unallocated space, you could shrink other
partition to generate the unallocated space.
The unallocated space should be adjacent to the partition you want to extend, no
matter it is before the target partition or behind it. If not, you could use the
feature "Move Partition" to adjust the position of it.
Step1. Install and launch AOMEI
Partition Assistant. In the main console you could view the whole partition
configuration. In this demonstrator, there is an unallocated space behind C drive.
Then, right-click the partition (here is C drive) you want to extend and select
Step2. In the pop-up window, position the mouse pointer on the right border of the
partition and drag the border rightwards to extend partition. Then click "OK".
(If there's no unallocated space beside the partition, you could not drag the
Step3. Then it will back to main console and you could preview the partition be
extended. Click the "Apply" on the toolbar to commit the operation.
The Merge partitions feature will not work on system reserved partition. If you
want to extend system reserved partition, you can Move the unallocated space to the
right side of the system reserved partition and then select Resize Partition.
Case 2: Shrink Partition
Shrinking partition could help you release some unused space from one partition and
get some unallocated space. After that, you could make new partitions and/or
increase other partition size with the unallocated space.
Step1. Install and launch
AOMEI Partition Assistant. In the main console you could view the whole partition
configuration. Then, right-click the partition (here is D) which you want to shrink
and select "Resize Partition".
Step2. In the pop-up window, position the mouse pointer on either border of the
partition and drag the border rightwards or leftwards to shrink partition. Then
Step3. Then it will go back to main console, and you could preview the unallocated
space beside the partition. Click the "Apply" on the toolbar to commit the
The partition shrinking operation will be performed under PreOS Mode
and your computer will
Shrink system and/or boot partition.
Shrink a partition on which the page file or AOMEI Partition Assistant
installation file is on.
Shrink a partition where applications are running. AOMEI Partition
Assistant will suggest you close them or perform partition shrinking
operation under PreOS Mode.