By AOMEI / Last Updated January 31, 2019

Suppose that you have spent a lot of time on building a personalized system with a lot of licensed applications and custom settings, you are very satisfied with the performance of the current system. Unfortunately, your system mat be crashed due to some reasons; It’s not a matter of whether your system will be crashed; it’s a matter of when. Therefore, in order to avoid the possibility, clone your operating system is your best choice. After cloning, you will have the benefits as follows:

  • You don’t have to reinstall operating system and applications when you upgrade hard disk from old and small one to new and large one.
  • You don’t have to reinstall operating system and applications when you encounter any serious problems, you can just restore your OS by cloning it back.
  • You can keep the cloned disk as a backup for later use.

Sometime we want to clone OS from the old hard drive to a new hard drive. But we have lots of data in it and don’t want to do the time consuming installing work. This pushes us into a dilemma. Can we clone OS (operating system) without reinstalling Windows and applications?

AOMEI Partition Assistant is such hard disk dive manager software. The Standard Edition is free for you to use and it is compatible with Windows XP, Vista, Windows 7, Windows 8 and Windows 8.1. AOMEI Partition Assistant simplifies the cloning process with the feature: copy partition and disk, which enable you to back up your essential partition or move partition from one hard disk to anther without losing data. Let me illustrate how to clone operating system to new hard drive with the free AOMEI Partition Assistant.

AOMEI Partition Assistant is an easy-to-use software even green hand can handle it. There are two partition copy methods:

  • "Copy Partition Quickly" - only copy the used space in the source partition and support to resize partition in the copy process (recommended). The size of unallocated space in destination disk should be equal or larger than the used space in the source partition.
  • "Sector-by-Sector Copy" - copy all sectors of the partition to another disk no matter whether it is used or not. The size of the unallocated space in the destination partition should be equal or larger than the source partition.

To begin, you need to free download AOMEI Partition Assistant Standard Edition. If you need to migrate OS from MBR to GPT or GPT to MBR/GPT, upgrade AOMEI Partition Assistant to Professional version. And after swtich from GPT to MBR or MBR to GPT, it is necessary to change boot mode.

Step1:Install and launch AOMEI Partition Assistant Standard Edition. Then, right click on the system partition and select Copy Partition.

Copy OS Partition

In the pop-up window, choose the partition copy method. Here we choose "Copy Partition Quickly" for example. And then click "Next" to continue.

Select Copy Method

Step2: Choose a destination space on your new hard drive. If your destination disk is an SSD, you need to check the option "Optimize the performance of SSD". Click Next.

Select Destination Space

It will pop-up a small window to remind you that you'd better use "Migrate OS to SSD" feature to realize copying the system partition to the destination disk. And click Yes, the program will move to migrate OS to SSD/HDD window, click No, it will continue the OS partition copy operation. Here we click No.

Click No

Step3: In the "Resize Partition" window, you can resize partition to fit the new hard drive. click Finish.

Resiz Partition OS

Step4: When you back to the main interface, you can see there is a partition marked as "Copy of C". Click Apply to execute the progress.

Apply OS Partition Copy


  • Only an unallocated space can be selected as the destination space.
  • OS cloning needs to be performed under PreOS Mode so reboot is required.

  • Disk Clone can be completed with Disk Copy Wizard, which is useful in replacing entire hard drive with new disk.

  • If there are other applications running on the partition which you are going to clone, AOMEI Partition Assistant will inform you to close those applications or to execute this operation under PreOS Mode.
  • If you select the “Copy Partition Quickly” method, the unallocated space could be smaller than the source partition but must be larger than the used space of the source partition. If you select the “Sector-by-Sector Copy” mode, the unallocated space must be equal or larger than source partition.

In addition to OS cloning features, there are lots of basic and advanced features in AOMEI Partition Assistant such as resize partition, move partition, merge partition, copy partition, windows to go creator and so on. You can Free download now and have a try.