An active partition is a partition on a hard drive set as the bootable
partition that contains the operating system. Only one partition on each hard
drive can be set as an active partition or bootable partition. For example, if
you are using Microsoft Windows the partition that contains Windows is the
can't make a logical drive or an extended partition active. Only a Primary
partition can be made active.
can be only one active partition per physical hard disk.
you have multiple hard disks installed on your computer, it's possible for
each hard disk to have a partition set as active. However, the active
partition on the first hard disk that your computer's BIOS detects is the
one that will start the computer.