Set active

If you have several primary partitions, you must specify one to be the boot partition. For this, one partition can be set as active. As a rule, a disk can have only one active partition.
 
To set an active partition:

1. 1. Select a primary partition to set as active from the list in the main window of EaseUS Partition Master.
2. 2. Select Partitions > Set active.  
3. 3. By clicking OK, you will add the pending operation of setting active partition.

Tips:

• Before you make a partition active, you must make sure it is formatted and contains an operating system. Otherwise your PC cannot boot from this partition!  
• If you set a partition as active and there was another active partition on the disk, it will be unset automatically. This might also prevent your PC from booting.