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:

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.

How to Run Windows 10 From a USB Drive

Loading and running Windows 10 from a USB drive is a handy option when you’re using a computer saddled with an older version of Windows.

You run Windows 10 on your own computer, but now you’re using another PC outfitted with an older operating system. If you prefer to use the newest version of Windows, though, there’s a way to run Windows 10 directly through a USB drive.

You’ll need a USB flash drive with at least 16GB of free space, but preferably 32GB. You’ll also need a license to activate Windows 10 on the USB drive. That means you have to either purchase one or use an existing one that is associated with your digital ID.

You can then use a Windows USB utility to set up the USB drive with Windows 10. Once you’re done, you’ll be able to boot up off the drive to launch Windows 10.

The major downside of booting from a USB drive is that Windows 10 will run slower than it does off your hard drive. But if you’re in a pinch you can at least work with the OS and access different apps this way.

Microsoft once offered its own tool called Windows to Go, which could generate a bootable Windows USB drive with the Enterprise and Education versions of Windows 10. However, the company has stopped development on that program and no longer updates it.

Instead, you can turn to two utility programs, WinToUSB and Rufus. These tools can create a bootable drive from any version of the operating system and on any type of USB drive.

Running Windows 10 From a USB Drive

If you want to run Windows from a USB, the first step is to sign into your current Windows 10 computer and create a Windows 10 ISO file that will be used to install the operating system onto the drive.

To do this, browse to the Download Windows 10 website. This site offers the latest edition of Windows 10, which at this point is the Windows 10 November 2019 Update, or Windows 10 version 1909.

Click the Download tool now button, then double-click the downloaded MediaCreationTool.exe file to install the program. At the first screen for Applicable notices and license terms, click the Access button. Then click the Create installation media (USB flash drive, DVD, or ISO file) for another PC button and hit Next.

At the Select language, architecture, and edition screen, confirm that all of the options are correct and then click Next.

You’ll then need to choose what media you want to use. Given the option between a USB flash drive and an ISO file, click ISO file. Then click Next.

Choose a location on your hard drive to store the Windows.iso file and click Save. Windows 10 will then generate the necessary ISO file. When the process is done, click Finish.

Running WinToUSB

Next, it’s time to enlist the aid of a third-party Windows USB program. Let’s kick things off with WinToUSB. This program comes in three flavors: Free, Professional, and Enterprise.

Start with the free version to see if you like it, but be aware that the freebie poses certain limitations. Most notably, you can create an installation of Windows 10 Home but not Professional or Enterprise.

If you need either of these editions, the Professional version of WinToUSB costs $29.95, while the Enterprise option will run you $199.95. Download and install the WinToUSB software from the dedicated website.

Next, connect a blank USB flash drive to your computer. Launch WinToUSB from its Start menu shortcut. At the introductory screen, click the button to the right of the Image File field and choose the ISO file you created for Windows 10.

Select the version of Windows 10 you wish to clone onto the USB stick. If you’re using the free version, your only choice is one of the Windows 10 Home versions, so select that one and hit Next.

At the next screen, you’ll need to determine your destination disk. Open the drop-down menu and choose your USB drive. A message pops up asking you to select a partition scheme. Click the MBR for BIOS option and hit Yes.

At the next screen, click the option for Legacy to choose the Installation mode. Click Next and your Windows 10 USB drive will now be created.

When the installation process reaches 100 percent, indicating that it’s finished, close the WinToUSB program and remove the USB drive.

Running Rufus

Now let’s check out Rufus. Download and install the Rufus program from its website, then launch the software. At the Drive Properties window, select your USB drive in the Device field, if it’s not already selected. Click the Select button next to the Boot selection field and select your Windows 10 ISO file.

Click the Image option field and change it to Windows to Go. You can leave the other options at their default values. If you wish, change the Volume label to something like Windows 10. Then click the Start button.

At the next screen, choose the version of Windows that you want to run on the USB drive, then click OK. A warning message flashes that all data on your USB drive will be destroyed. Click OK to continue.

Rufus will now copy the necessary files to the USB drive. After the USB drive has been set up, close the Rufus window.

Launch Windows 10 With USB

When you want to launch Windows 10 on a different computer, insert your USB drive into that PC. Press the appropriate key to launch your Boot menu and choose the option to boot up off the USB drive. The easiest way is to hold the Shift key and restart the computer.

The first time you run Windows 10 off the USB drive, you’ll need to go through the familiar Windows setup process. You’ll also need to activate Windows 10.

You can then install apps onto the USB drive and access any files or documents stored online, so the experience comes close to working on one of your own Windows 10 PCs.