Whether you are in the process of troubleshooting your computer or installing a new operating system, you may need to boot from a USB device. If you are unfamiliar with this process, here is what you need to know and how to do it.
When you hold the power button on your computer, it boots up from the internal hard drive, where the operating system (Windows or macOS) resides.
If you are reading this, it means you probably need to boot into something else. Maybe you need to reinstall Windows – perhaps you need to boot from a system rescue disc to resolve a hardware issue with your device, or want to install and run a different operating system on your device.
How to Boot From USB on a Windows PC
Not every Windows PC is the same. Some PCs are designed to search for a USB before reverting to the operating system on the internal hard disk. Here’s how to boot from a USB drive on a PC:
Restart Your Device
Restart your PC and wait for that first screen to pop up. Usually, it will tell you to Press F12 to Choose Boot Device — the function key may change depending on your PC. Hit that key!
Give It a Second
Give it a minute to proceed with the booting. A menu should then pop up with a listing of options. Choose your preferred CD or USB drive and hit Enter.
Alternatively, you can program your computer to regularly check for a bootable USB drive and adjust the boot sequence. That way, when you have an external disc plugged in, your PC will automatically boot from it. To set it up, follow these directions.
Restart your PC and wait for the opening screen that pops up when you boot. You should see a message like “Press DEL to enter SETUP” or something of the sort. Hit the requested key on your keyboard and wait for the setup to begin.
Choose ‘Boot Device’
You will be prompted with a new screen called your BIOS. This is where you can program low-level settings for your PC. BIOS interfaces vary across devices, but you should see some directions for operating yours, such as which keystrokes to use.
Using those directions, scan through your menu options for a setting named “Boot Device,” “Boot Order,” or something of that nature. Choose that option.
Choose the Correct Drive
Upon clicking Boot Device, a new screen should pop up where you will choose your PC’s disc drive – press Enter. If you want to boot from a USB drive, pick that option instead. It might be placed on its own or under a sub-list like “Removable Devices.” Depending on your BIOS configuration, you may need to work with the Page Up and Page Down or +/- keys to choose your selection.
NOTE: Again, directions may vary depending on your BIOS.
Exit the BIOS
Follow the requested directions to quit your BIOS and save the new changes. Usually, this option is listed under “Exit” or “Save and Exit” on the primary menu or accessible via a keyboard shortcut noted somewhere on the screen. Depending on your BIOS, you may have to verify your confirmation before you head out.
Your PC should then restart automatically after that. Make sure your USB drive is inserted into your computer. If you’re requested to “Press any key to boot from the external device,” hit something. Your computer will boot into the USB drive instead of the operating system.
From there, you can follow the directions on the screen to reinstall Windows, troubleshoot, or whatever else it is you need to do.
How to Boot From USB on a Mac
Booting from a USB is surprisingly easy on a Mac. Here is how to do it. Open System Preferences > Startup Disk. There you’ll see your built-in hard disk as well as any external drives and compatible operating systems.
Press the lock symbol at the bottom-left corner of the window. Type in your admin password, choose the startup disk you want to boot from and click Restart.
Doing so will save your startup disk preference until you change it to something else. To do a one-time boot from an external hard drive, you’ll need to use the Startup Manager instead. Here’s how to do it:
Reboot Your Computer
Restart your computer. Press and hold the Option key as soon as your Mac turns back on. Release when the Startup Manager window pops up or when you are prompted to enter your firmware passcode.
Choose the Correct Drive
There, you should see icons for your open drives. On the right, you’ll see your external drive with its name listed under it. Using your arrow keys or your mouse, highlight your USB, then hit Return or click on the arrow underneath it. To save the USB as your preference, press and hold Control, and your computer will take care of the rest.
From there, your Mac will boot into the USB drive instead of the operating system, and you can proceed with whatever it is you need to do by following the on-screen directions.
Booting your computer or Mac from a USB device sounds more dramatic and complicated than it really is. Sometimes it’s a necessary process in solving issues in your device, among other things. Hopefully, this guide will help you achieve whatever it is you need with your device. For more handy tech guides, check out our blog page.