How to boot from usb

How to Boot From a USB Device

Make your PC boot from a USB flash drive or external hard drive

What to Know

When you boot from a USB device, you’re running your computer with the operating system installed on the USB device. When you start your computer normally, you’re running it with the operating system installed on your internal hard drive—such as Windows, Linux, or macOS.

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.

These instructions assume you already have a bootable flash drive ready to go, but if not we have a guide on how to create a bootable USB flash drive of OS X Mavericks Installer.

Change the boot order in BIOS so the USB device option is listed first. The BIOS is rarely set up this way by default.

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.

The BIOS on most computers lists the USB boot option as USB or Removable Devices, but some confusingly list it as a Hard Drive option, so be sure to dig around if you’re having trouble finding the right one to choose.

After setting your USB device as the first boot device, your computer will check it for boot information each time your computer starts. Leaving your computer configured this way shouldn’t cause problems unless you plan on leaving the bootable USB device attached all the time.

Attach the USB device to your computer via any available USB port.

Creating a bootable flash drive or configuring an external hard drive as bootable is a task in itself. Chances are you made it to these instructions here because you know whatever USB device you have should be bootable after properly configuring BIOS.

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.

Watch for a Press any key to boot from external device. message.

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.

Most of the time, when trying to boot from a USB device, there is no key-press prompt. The USB boot process usually starts immediately.

Your computer should now boot from the flash drive or USB based external hard drive.

What happens now depends on what the bootable USB device was intended for. If you’re booting from Windows 11, Windows 10, etc. installation files on a flash drive, the operating system setup will begin. If you’re booting from a DBAN flash drive you created, it will start. You get the idea.

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.

Recheck the boot order in BIOS (Step 1). The number one reason a bootable flash drive or another USB device won’t boot is that BIOS isn’t configured to check the USB port first.

Didn’t find a «USB Device» boot order listing in BIOS? If your computer was manufactured around 2001 or before, it might not have this ability.

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.»

Remove other USB devices. Other connected USB devices, like printers, external media card readers, etc., could be consuming too much power or causing some other problem, preventing the computer from booting from a flash drive or another device. Unplug all other USB devices and try again.

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.

Copy the files to the USB device again. If you created the bootable flash drive or external hard drive yourself, which you probably did, repeat whatever steps you took again. You may have made a mistake during the process.

If you started with an ISO image, burn the ISO file to a USB. Getting an ISO file onto a USB drive, like a flash drive, isn’t as easy as just expanding or copying the file there.

Switch to another USB port. The BIOS on some motherboards only checks the first few USB ports. Switch to another USB port and restart your computer.

Update your motherboard’s BIOS. If your computer is ancient, the BIOS version running on the motherboard may not support booting directly from a USB device. Try updating the BIOS and checking again for this feature.

BIOS stands for Basic Input/Output System. It’s the built-in core processor software responsible for booting up your computer.

Insert the USB device into an open slot. Turn on or restart your Mac, then press and hold the Option key to open Startup Manager. Find and select the USB you wish to boot from.

Install Windows from a USB Flash Drive

This topic covers how to manually create a Windows installation USB drive from Windows installation ISO disc image file or DVD, and is intended for PC manufacturers looking into creating media that they can use to manufacture Windows devices.

The steps described on this page assume you have Windows installation media and access to a Windows technician PC. If you’re looking for an easy, automated way to create a bootable USB Windows installation drive, see:

What you need

Connect the USB flash drive to your technician PC.

Open Disk Management: Right-click on Start and choose Disk Management.

Format the partition: Right-click the USB drive partition and choose Format. Select the FAT32 file system to be able to boot either BIOS-based or UEFI-based PCs.

FAT32 has a file size limit of 4GB If your WIM image is larger than 4 GB, see If your Windows image is larger than 4GB below.

Set the partition as active: Right-click the USB drive partition and click Mark Partition as Active.

If Mark Partition as Active isn’t available, you can instead use diskpart to select the partition and mark it active.

Use File Explorer to copy and paste the entire contents of the Windows product DVD or ISO to the USB flash drive.

Optional: add an unattend file to automate the installation process. For more information, see Automate Windows Setup.

Connect the USB flash drive to a new PC.

Turn on the PC and press the key that opens the boot-device selection menu for the computer, such as the Esc/F10/F12 keys. Select the option that boots the PC from the USB flash drive.

Windows Setup starts. Follow the instructions to install Windows.

Remove the USB flash drive.

If your Windows image is larger than 4GB

Windows USB install drives are formatted as FAT32, which has a 4GB filesize limit. If your image is larger than the filesize limit:

Copy everything except the Windows image file (sources\install.wim) to the USB drive (either drag and drop, or use this command, where D: is the mounted ISO and E: is the USB flash drive.)

Split the Windows image file into smaller files, and put the smaller files onto the USB drive:

Digital Citizen

How to boot from a USB drive (4 ways)

There are many situations in which you might want to boot your computer using a USB flash drive. Maybe because you need to install Windows on your PC or maybe because you want to try the latest version of your favorite Linux distribution. Whatever reasons you might have, here are three different ways to use a bootable USB flash drive to start your computer:

NOTE: If you want to boot from USB in order to install Windows 10 or Windows 11, you’ll first need to create the Windows installation drive. If you’d like guidance on that, check these tutorials: Windows 10 Media Creation Tool: Create a setup USB stick or ISO or Windows 11 Media Creation Tool: Create a setup USB stick or ISO.

1. How to boot from a USB drive using Windows 10’s Settings (without BIOS or UEFI)

Start by plugging in the bootable USB flash drive to a USB port on your computer. Then, open the Settings app and head to Update & Security.

Update & Security settings in Windows 10

Select Recovery on the left, and then scroll on the right side of the window until you find the Advanced startup section. In it, click or tap the Restart now button.

Advanced startup recovery options in Windows 10

Windows 10 restarts and then shows a screen where you can Choose an option. Click or tap on Use a device.

Choosing to use a device to start the PC

Next, you should see a list of devices your computer can boot from, including the USB flash drive that you plugged in. Click or tap on it.

Selecting the USB flash drive from which the PC should boot

Your computer then restarts and boots from the USB flash drive you chose.

TIP: If you want a faster way of accessing the Windows recovery environment, from where you can boot from a USB drive, creating a shortcut or knowing the command for that might come in handy. Here’s a guide that explains everything: Shortcuts for the UEFI BIOS & Windows 10’s Recovery Environment.

2. How to boot from a USB drive using Windows 11’s Settings (without BIOS or UEFI)

First, connect the bootable USB flash drive to a USB port on your Windows 11 computer. Then, open Settings (Windows + I), ensure that System is selected on the left sidebar, and click or tap on Recovery on the right panel.

Access the Recovery settings in Windows 11

Also on the right side of the window, locate the Advanced startup option. It briefly explains that you can “Restart your device to change startup settings, including starting from a disc or USB drive.” Press the Restart now button on the right.

Advanced startup in Windows 11

Next, Windows 11 will let you know that it will restart your device, so you’d better save your work before that. After doing so, click or tap the Restart now button from the dialog.

Windows 11 notifies you that it will restart your device

Your PC will then reboot, and Windows 11 will load its recovery environment. In it, select the Use a device option.

The Use a device option in Windows 11’s recovery environment

Next, you’ll see the list of bootable devices your computer can use. That includes the USB drive you’ve plugged in, so click or tap on it.

Choose to boot Windows 11 from the USB drive

Finally, your computer restarts and then boots from the USB drive you’ve chosen earlier.

3. How to boot from a USB drive using the UEFI/BIOS Boot Menu

If you are lucky, then all that you must do to boot from a USB flash drive, regardless of the operating system installed on your PC, is choose the USB flash drive from the Boot Menu of your UEFI or BIOS. Make sure that your USB flash drive is bootable, and then plug it into any USB port on your computer.

Next, power on your computer (or restart it if it is on). Immediately after powering it on, when the BIOS/UEFI screen appears, access the Boot Menu by pressing the right key(s) for it. Most PC manufacturers use the F8, F9, F10, or F11 keys for that, and many computers show the Boot Menu key(s) right after you power them on. However, if you cannot identify the right one, check the documentation for your computer’s motherboard or device manufacturer. The Boot Menu access key(s) should be mentioned in their user manuals.

Once the Boot Menu appears on the screen, use it to select the USB flash drive from which you want to boot and press Enter on your keyboard. Note that the USB flash drive can bear different names depending on what the PC or motherboard manufacturer wanted. Some list it as Removable Device, some as USB-HDD, and so on.

Selecting to boot from a USB flash drive in the Boot Menu

Once you’ve pressed Enter, the computer should boot from the USB flash drive.

4. How to boot from a USB drive by modifying the UEFI/BIOS settings

Start by accessing your BIOS/UEFI. You should be able to do that by pressing the right key (combination) immediately after you power on your PC. Although the manufacturer of your PC or motherboard can assign any key for this action, commonly used keys include Delete, F1, F2, F10, and F12. If none of these works, you can find the right key to press in the manual of your PC or motherboard.

If your PC has UEFI (a newer type of BIOS), it may boot so fast that you do not have time to press any key to access it. In such a situation, follow the steps from these guides, depending on what version of Windows you have:

Moving the USB flash drive to the top of the boot order list

After you’ve selected the USB flash drive as the first boot option, save your settings (usually done by pressing F10 on your keyboard) and Exit the BIOS/UEFI environment. Your computer will restart and then automatically boot from the USB flash drive.

Saving the settings in BIOS/UEFI

IMPORTANT: If your computer uses UEFI, you might not be able to make the previous settings. In that case, you must first disable (temporarily) the Secure Boot option. This option can also have different names depending on what the manufacturer wanted: Legacy Boot or Legacy Support, CSM or Launch CSM, and so on. Choose to enable the options that start with Legacy or which have CSM in their names.

What’s your favorite method to boot from a USB flash drive?

Now you know a couple of different ways to boot your computer using a USB flash drive. Which of them is your favorite? Do you use the options built into Windows 10 and Windows 11, or do you prefer to do it from BIOS/UEFI? Did you manage to boot your PC from a USB drive? If you did not, what went wrong? Let us know in the comments section below.

How to Set Your Computer to Boot from USB Flash Drive

wikiHow is a “wiki,” similar to Wikipedia, which means that many of our articles are co-written by multiple authors. To create this article, 22 people, some anonymous, worked to edit and improve it over time.

The wikiHow Tech Team also followed the article’s instructions and verified that they work.

This article has been viewed 441,806 times.

A bootable USB flash drive is useful for installing an operating system or diagnosing system problems. But once you have your bootable USB flash drive, how can you boot from it? This wikiHow teaches you how to start up your Windows PC or Mac from a USB flash drive.

\u00a9 2022 wikiHow, Inc. All rights reserved. wikiHow, Inc. is the copyright holder of this image under U.S. and international copyright laws. This image is not licensed under the Creative Commons license applied to text content and some other images posted to the wikiHow website. This image may not be used by other entities without the express written consent of wikiHow, Inc.
\n

\u00a9 2022 wikiHow, Inc. All rights reserved. wikiHow, Inc. is the copyright holder of this image under U.S. and international copyright laws. This image is not licensed under the Creative Commons license applied to text content and some other images posted to the wikiHow website. This image may not be used by other entities without the express written consent of wikiHow, Inc.
\n

I edited this screenshot of a Windows icon.\n

While fans of different operating systems might debate which one is the most stable, reliable, flexible or user-friendly, there’s one inarguable point: Every machine – regardless of the OS – can run into issues.

And while users historically would pop a boot media disk into their DVD or CD drive, many computers no longer come with optical disk drives. As a result, booting from USB media is becoming the standard. How you start that rescue media can vary depending on the operating system you are using, but there are a few general guidelines that can help get your machine started, regardless of the OS you prefer. So if your system is unstable, you need to run a diagnostic tool on the hard drive, or you just want to load a Linux desktop just to see what it’s all about, let’s look at how you start your machine using rescue USB boot media.

How to boot a Mac from USB: Steps

Getting your Mac to load from a USB drive is fairly straightforward.

NOTE: Have multiple USB devices connected to your Mac? Don’t worry. The Startup Manager only lists drives that include bootable content.

How to Boot from USB on Windows?

Starting your PC using USB rescue media is not difficult, although it first requires an adjustment in the BIOS (Basic Input Output System). That’s because the BIOS settings include the boot sequence the machine follows when starting up. The boot order tells the machine which devices to search for the software needed to launch the computer and the priority each device in that search. If you’re booting from USB media, you must change the BIOS boot order so the USB device is listed first. Otherwise the computer will load from the hard drive as normal. Start by plugging the thumb drive into a USB port. Then to change the BIOS boot sequence:

How to boot from USB on Linux?

To boot Ubuntu from USB media, the process is very similar to the Windows instructions above.