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Partition/Data Recover

Set Active Partition- Partition Assistant Help

Typically, your disk always has only active partition. A Windows operating system need to be booted from the active partition.

AOMEI Post By AOMEI Updated May 13, 2024

Overview of set active partition

You may have multiple primary partitions (at most 4) on your hard disk drive, active Partition refers to a primary partition that contains boot files of the operating system. After you make a partition as active, the operating system will hence start from that partition. Typically, a disk can have one and only one active partition.

Before you do

Make sure it contains the loader (an operating system tool) or boot files such as "boot.ini", "ntldr", "bootmgr" or "BCD" before you mark that partition as active.
If there are other applications running on the partition which you are going to perform, AOMEI Partition Assistant will notify you to close those applications.
Never make a partition that contains no system files as active. Doing so will cause your computer to stop working.
Tips: This operation can ensure absolute security for your data.

How to set active partition

1. Launch AOMEI Partition Assistant. Right-click on the partition you want to mark as active and select "Advanced" -> "Set Active Partition"

Set Active Partition

2. A reminderwill be presented in the main window. Click "OK".


3. Click "Apply" to open the pending operations as shown in the screenshot below. You will get a reboot warning, click "Proceed" to start the operation.



  • You can't make a logical drive or an extended partition active. Only a primary partition can be set as active.
  • Your computer can only boot from the main partition which is set active, and there can be only one active partition per physical hard disk drive.