Step 5: Boot from USB on Surface Pro

Start from a bootable USB device when Surface is off

Step 1: Attach a bootable USB device to the USB port.

Step 2: Press and hold the volume-down (–) rocker.

Step 3: Press and release the power button.

Step 4: When the Surface logo appears, release the volume rocker. Surface will start the software on your USB device.

Start from a bootable USB device when Surface on

Step 1: Attach a bootable USB device to the USB port.

Step 2: Swipe in from the right and then tap Settings.

(If you're using a mouse, point to the upper-right corner of the screen, move the mouse pointer down, and then click Settings.)

Step 3: Tap or click Change PC Settings.

Step 4: Tap or click Update and recovery, and then tap or click Recovery.

Step 5: Under Advanced Startup, tap or click Restart now.

Step 6: On the Choose an option screen, tap or click Use a device.

Step 7: On the Troubleshoot screen, tap or click Advanced options.

Step 8: On the Advanced options screen, tap or click the name of the USB device. Surface will restart and boot from the USB device.

*Instructions from http://www.microsoft.com/surface/en-us/support/storage-files-and-folders/boot-surface-pro-from-usb-recovery-device