How to Boot From a USB Device
Follow these steps to boot from a flash drive, an external hard drive, or some other bootable USB device. It should take anywhere from 10 to 20 minutes, depending on if you have to make changes to how your computer starts up.
What to Do When the USB Device Won’t Boot
If you tried the above steps, but your computer didn’t boot from the USB device, check out some of the tips below. There are several places that this process can get hung up at. If the USB boot option is not first in the boot sequence, your PC will start “normally” (i.e., boot from your hard drive) without even looking at any boot information that might be on your USB device. Since you’re not actually inside of the operating system at this point, restarting isn’t the same as using normal restart buttons. Instead, BIOS should explain which key to press—such as F10—to save the boot order changes and restart the computer. You may be prompted with a message to press a key on some bootable devices before the computer boots from the flash drive or another USB device. If this happens, and you do nothing, your computer will check for boot information on the next boot device in the list in BIOS (see Step 1), which will probably be your hard drive. If your computer is newer, check for some other ways that the USB option might be worded. In some BIOS versions, it’s called “Removable Devices” or “External Devices.” Or, if you have multiple bootable devices plugged in at once, the computer might simply be booting to the wrong device, in which case the easiest fix would be to remove all USB storage devices but the one you want to use right now.
