How to Boot From a USB Device

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

There are lots of reasons you might want to boot from a USB device, like an external hard drive or a flash drive, but it’s usually so you can run special kinds of software.

When you boot from a USB device, what you’re doing is 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—Windows, Linux, etc.

Time Required: Booting from a USB device usually takes 10–20 minutes, but it depends a lot on if you have to make changes to how your computer starts up.

How to Boot From a USB Device

Follow these easy steps to boot from a flash drive, an external hard drive, or some other bootable USB device.

If the USB boot option is not first in the boot order, 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.

See our How to Burn an ISO File to a USB Drive tutorial for general instructions on doing exactly that, which tends to be the reason most people need to figure out how to boot from one.

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 10, Windows 8, or Windows 7 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.

See How to Burn an ISO File to USB if you started with an ISO image. 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 flashing the BIOS and checking again for this feature.

Install Windows from a USB Flash Drive

Here’s how to create a bootable Windows installation USB drive starting with a Windows .iso file or a Windows Setup DVD.

If you’re looking for an easy way to create a bootable USB Windows installation drive, use the media creation tool.

What you need

• Windows 10 install .iso or DVD
• USB flash drive with at least 5GB free space. This drive will be formatted, so make sure it doesn’t have any important files on it.
• Technician PC — Windows PC that you’ll use to format the USB flash drive
• Destination PC — A PC that you’ll install Windows on

Step 1 — Format the drive and set the primary partition as active

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.

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.

Step 2 — Copy Windows Setup to the USB flash drive

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.

Step 3 — Install Windows to the new PC

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:

Включаем загрузку с флешки в разных версиях BIOS

Загрузиться с флешки можно и без изменения настроек BIOS — с помощью Boot Menu или особых вариантов загрузки. Однако эти способы не всегда работают. Поэтому приходится менять приоритет загрузки. Мы собрали варианты для разных моделей материнских плат и версий BIOS, которые помогут загрузиться с флешки при включении компьютера.

Использование Boot Menu

На большинстве материнских платах есть Boot Menu. Оно позволяет выбрать загрузку с флешки без изменения настроек BIOS. Для запуска Boot Menu нужно после включения системы нажимать на определённую клавишу.

• Стандартные варианты клавиш — Esc, F11, F12.
• На материнских платах ASUS обычно используется клавиша F8.
• На ноутбуках и моноблоках Acer — F9 или сочетание клавиш Esc+F9.
• На ноутбуках Lenovo — физическая кнопка на корпусе с изображением стрелки.

Часто клавишу для запуска Boot Menu можно увидеть на той же странице, что и кнопку для входа в BIOS. После нажатия правильной кнопки появляется список устройств, с которых можно загрузиться. Для перемещения по нему используем стрелочки, а для выбора флешки — клавишу Enter.

К сожалению, воспользоваться Boot Menu удаётся не всегда. В таком случае приходится менять приоритет загрузки в BIOS. Это точно можно сделать на всех материнских платах.

Изменение приоритета загрузки в BIOS

О том, как заходить в разные версии BIOS, мы рассказывали в подробной статье. В ней указаны разные комбинации клавиш для перехода в интерфейс базовой системы. Здесь мы рассмотрим решение конкретной задачи внутри BIOS — изменение приоритета загрузки.

Phoenix AwardBIOS

Это старая версия BIOS, которая встречается в двух модификациях.

Начнём с первой — у неё преимущественно синий интерфейс. Для навигации используются стрелки и клавиша Enter.

1. Переходим в раздел «Advanced BIOS Features».
2. Выбираем пункт «Hard Disk Boot Priority».

3. С помощью клавиши «+» перемещаем USB-устройство на первую строчку.

4. Возвращаемся в предыдущее меню с помощью клавиши Esc.

5. В строке «First Boot Device» выбираем значение «USB-HDD». Если такой записи нет, то ставим «USB-FDD» или «USB-CDROM».

6. Для параметра «Second Boot Device» выставляем значение «Hard Disk».

7. Нажимаем клавишу F10 и подтверждаем сохранение конфигурации,

после чего компьютер перезагрузится.

У другой версии Phoenix AwardBIOS интерфейс серого цвета и немного другое меню. Но принцип остаётся прежним:

1. Переходим в раздел «Advanced».
2. Выбираем пункт «USB Configuration».
3. Устанавливаем для параметра «USB Controller» значение «Enabled». Если оно и так стоит, то ничего не трогаем.

4. Возвращаемся в предыдущее меню с помощью клавиши Esc.

5. Открываем вкладку «Boot».

6. Переходим в раздел «Hard Disk Drives».

7. Перемещаем подключенную флешку на первую строчку с помощью клавиши «+».

8. Возвращаемся в предыдущее меню.

9. Открываем раздел «Boot Device Priority».

10. Параметру «1st Boot Device» задаём значение «HardDisk».

На этой версии BIOS иногда работает другой вариант — для загрузки с флешки достаточно зайти в раздел «Boot» и в строке «1st Boot Device» выбрать значение «USB».

Если настройки выставлены правильно, то после перезапуска компьютер загрузится с флешки.

AMI BIOS

Ещё одна версия BIOS, в которой приоритет загрузки настраивается почти так же, как на AwardBIOS.

1. Открываем раздел «Advanced» и выбираем подраздел «USB Configuration».
2. Параметру «USB Function» задаём значение «Enabled». Если оно уже стоит, ничего не меняем.
3. Возвращаемся на стартовое окно и выбираем вкладку «Boot».
4. Открываем раздел «Removable Drives» (иногда нужно заходить ещё и в раздел «Hard Disk Drives»).

5. Нажимаем на пункт «1st Drive» и выбираем из списка загрузочную флешку.

6. Переходим в раздел «Boot Device Priority».

7. Выбираем в строке «1st Boot Device» загрузочную флешку.

3 ways to boot your Windows 10 PC from a USB flash drive

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:

1. Use Windows 10’s Settings to make your PC boot from a USB flash drive

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.

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.

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

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

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

2. Use the Boot Menu to select the USB flash drive as the first boot option

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 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 was 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 your 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.

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

3. Use the BIOS/UEFI to change the boot devices order and move the USB flash drive to the top of the list

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 choose whatever key it wants you to press, 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 described here: How to access the UEFI BIOS Firmware on Windows tablets, laptops and convertibles.

Once you have entered the BIOS/UEFI, browse through its configuration options until you find a page called Boot or similar. There you should see the boot order used by your computer. In this list, you must choose the USB flash drive to be the first device used for booting. Remember that the USB option can be named differently on your PC: check for Removable Devices, USB-HDD or similar names. Moving the USB flash drive to the top of the boot list is usually done using the keyboard keys +, -, F5 or F6. Your BIOS/UEFI should display some helpful information about this topic.

Once you have chosen the USB flash drive as the first boot option, save your settings (usually done by pressing F10 on your keyboard) and Exit BIOS/UEFI. Your computer should restart and then automatically boot from the USB flash drive.

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.

Which is your favorite method to boot from a USB flash drive?

Now you know three different ways to use a USB flash drive to boot your computer. Which of them is your favorite? Do you use the options built into Windows 10, 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? Comment below and let’s discuss.