How to Set an External HDD to Active

by Amanda Rumble

An external hard disk drive is portable and connects to your computer via a USB cable. When your computer has multiple hard drives, one of the hard drives or partitions on the hard drive must be marked as active in order for an operating system to boot. Set both internal and external hard drives as active through the built-in Computer Management Tool in Windows 7.

Step 1

Click "Start" (the Windows-logo button on the lower-left-hand corner of the screen) and select "Control Panel" from the menu.

Step 2

Click the "System and Security" option.

Step 3

Scroll to the bottom of the page and select "Administrative Tools."

Step 4

Double-click "Computer Management" to open the various management options.

Step 5

Select "Disk Management" located on the left-hand side to display a listing of your hard drives and their statuses.

Step 6

Scroll through the list of your hard drives and right-click on your external hard drive.

Select "Mark Partition as Active."


  • Always be sure that the partition or hard drive you mark as active has your operating system's files on it. Otherwise, your system may become unbootable.


  • If your hard drive has multiple partitions, only one can be marked as active. Only the primary hard drive partition can be marked as active. You cannot mark a logical or extended partition as active.
  • You need administrative privileges to make any changes through disk management.


About the Author

Amanda Rumble has been writing for online publications since 2000, primarily in the fields of computing and technology. She holds a bachelor's degree from the University of Buffalo in information technology. Rumble also focuses on writing articles involving popular video games and Internet culture.

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