How to Make an External Drive Your Main Hard Drive

By Rebecca O'Brien

In order to set an external hard drive as the main hard drive of your computer, you need to make a few changes to the computer's BIOS. These changes are helpful if your internal hard drive has failed or has become corrupted. You can also use this method to circumvent the need for a boot manager, and simply use various external hard drives, loaded with different operating systems, to boot your computer.

Step 1

Prepare the USB drive. Install your operating system of choice to the USB drive. Also install any necessary drivers, their updates and operating system updates.

Step 2

Prepare your computer. Access your computer's BIOS and navigate to the Boot Order menu. This lists all available boot devices. Using the commands listed on the BIOS screen, select the option that resembles "USB device" from the list and move that to the top position.

Step 3

Shut down your computer.

Step 4

Attach your external USB hard drive. Plug this drive in to any of the available USB ports. If you are permanently attaching the drive to a desktop, use a rear USB port to protect the cable.

Step 5

Test the USB hard drive. Boot your computer to ensure the USB hard drive is successfully recognized. Also check the drive letter assignments for the built in hard drive and the CD-ROM (if present).