By AOMEI / Last Updated May 15, 2020

Why Need to Extend System Partition before Upgrading to Windows 10

Most PC users have the system partition, which is also known as C: drive, allocated around 30GB. while installing apps especially the ones require large disk space, you may find out the system partition is running out of space. Those people who want to get Windows 8 or Windows 7 upgrade to Windows 10 need to pay extra attention to it for Windows 10 installation and operation needs about 8GB free spaces, so it is quite necessary to extend C drive for upgrading windows10.

The Limitations of Disk Management

The Windows built-in tool, Disk Management, is capable of extending system partition. To open Disk Management, click Server Manager>Storage>Disk Management. Then right-click the C: drive, and click Extend Volume to do the rest as instructed. It is quite convenient to extend system partition before upgrading to windows 10 with Windows built-in tool, but the Extend Volume option might be grayed out, because Disk Management allows you to extend a partition only if there is contiguous unallocated space next to its right. What’s worse, the only way to create the unallocated space needed for extending partition is to delete the partition next to its right side. Therefore, you may consider using another disk manager software that is more flexible and easy to understand to extend system partition.

Extend Partition with AOMEI Partition Assistant

AOMEI Partition Assistant Standard, free disk manager software, is one of the best solution to resize partition before installing windows 10 for which allows you to use any unallocated space on the same hard disk to extend a partition. With the feature, Move Partition, implemented, you can shrink a partition from both sides to create unallocated space.

1. Install and launch AOMEI Partition Assistant Standard. Right click the partition you want to shrink and select Resize Partition. If there is already unallocated space on the system disk, you can click Merge Partitions to allocate the unallocated space into C: drive.


2. In the Move and Resize Partition screen, you can move the sliders on both sides to shrink the partition. You can also enter the specific amount to create unallocated space as the instruction states. Then click OK to move on. At this stage, you can either click Apply to execute the process or wait till all the operations are well set.


3. Right-click the C: drive and select Resize Partition. In the pop-out window, move the slider rightwards to extend partition. Then click OK. You can use all the unallocated spaces on the disk no matter where they are located.


4. You can view the pending tasks. If this is what you want, click the Apply to execute the operations.


Before you extend C drive for upgrading windows10, you'd better defrag the partitions and check disk errors in need of a smooth and quick performance. Your computer may need to reboot into PreOS to complete the process. If you do not want to reboot your computer, you can choose Extend Partition Wizard in AOMEI Partition Assistant. In this way, you can extend your system partition without rebooting unless there are page files or applications running on the involved partition, except system C: drive.