How to Burn an ISO File to a USB Drive

The free Rufus tool can be used to 'burn' an ISO image to a USB flash drive

What to Know

  • Download and open Rufus tool. Insert a USB drive and select a device. Select Disk or ISO image. Locate and select ISO image to burn.
  • Under Image option, choose Standard Windows installation. Leave other options alone and choose Start.
  • Wait for the status to say "Ready," then close Rufus and remove the USB drive.

This article explains how to put an ISO image on a flash drive so you can properly boot from it to install an operating system or run some other bootable program.

This process also works to burn a Windows 11 ISO to USB. However, doing so via Microsoft's Windows 11 media creation tool is best.

Time Required: "Burning" an ISO image file to a USB device, like a flash drive, usually takes less than 20 minutes, but the total time depends a lot on the size of the ISO file.

How to Burn an ISO to USB With the Rufus Tool

So you have an ISO file that you want on a flash drive or some other USB storage device. You also need to be able to boot from it. Sounds straightforward, right? Copy the file over and you're done! Unfortunately, it's not that simple.

Properly burning an ISO to USB is different than copying the file or burning it to a disc. With ISO burning, you're not technically "burning" anything to a USB drive. Adding to the complexity is that you plan on booting from the USB drive once you're done getting the ISO image on there.

  1. Download Rufus, a free tool that will correctly prepare the USB drive, automatically extract the contents of the ISO file you have, and properly copy the files contained within it to your USB device, including any files in the ISO needed to make it bootable.

    Download page for Rufus 3.4 Portable

    Rufus is a portable program (doesn't install), works on Windows 11, 10, 8, and 7, and will "burn" an ISO image file to any type of USB storage device you happen to have.

    If you'd prefer to use a different ISO-to-USB tool, some other good ones include balenaEtcher, UNetbootin, and Universal USB Installer. Of course, if you do choose another program, you won't be able to follow the instructions we've written here because they pertain specifically to Rufus.

  2. Open the version of Rufus you downloaded. The program will start right away.

    Rufus-3.4p idon in File Explorer on Windows 10

    As we mentioned earlier, Rufus is a portable program, meaning that it just runs as is. This is a big reason why we prefer this ISO-to-USB program over some of the other options out there.

    When it first opens, you're asked whether the program should occasionally check for updates. It's up to you whether you want to enable this, but it's best to do so if you plan to use it again in the future.

  3. Insert the flash drive or other USB device into your computer that you want to "burn" the ISO file to, assuming it's not already plugged in.

    Using Rufus to put an ISO image to a USB drive will erase everything on the drive! Before continuing, check that the drive is empty or that you've backed up any files you want to keep.

  4. From the Device drop-down at the top of the program, choose the USB storage device you want to burn the ISO file to.

    Device to "burn" iso onto

    Rufus tells you the size of the USB device, as well as the drive letter and current free space on the drive. Use this information to double-check that you're choosing the correct device, assuming you have more than one plugged in. Don't worry about the free space that's indicated, since you'll be erasing the entire drive as part of this process.

    If no drive is listed, or you can't find the one you're expecting to see, there might be an issue with the USB device you're planning on using for the ISO image, or Windows is having some sort of problem seeing the drive. Try another device and/or another USB port on your computer, or close and reopen Rufus.

  5. From the Boot selection drop-down, make sure Disk or ISO image (Please select) is chosen.

  6. Choose SELECT.

    Select button for Boot selection iSO file

    If this button says DOWNLOAD instead, select the arrow next to it to find SELECT.

  7. Locate and select the ISO image you want to burn to the flash drive, and then press Open to load it into Rufus.

    Open button with Windows10 ISO selected in File Explorer
  8. Wait while the software inspects the ISO file you chose. This might take several seconds or may go by so quickly that you don't even notice.

    If you get an Unsupported ISO message, the ISO you chose isn't supported for burning to USB by Rufus. In this case, try one of the other programs listed in Step 1 or check with the maker of the ISO image for more help getting their software to work from a USB drive.

  9. Under the Image option area, pick Standard Windows installation if you see this and if that's the case.

    For example, if you're putting a Windows installation ISO image onto the flash drive, and you get this option, you'd want to enable it for sure.

  10. Leave the Partition scheme, Target system, File system, and Cluster size options alone unless you know what you're doing or you've been advised to set any of those parameters to something else.

    For example, maybe a bootable tool you downloaded in ISO format advised on its website to make sure the file system is FAT32 instead of NTFS if you're burning to USB. In that case, make that change before continuing.

  11. You're welcome to enter a custom volume label in the Volume label field, but leaving it at whatever the default happens to be, or even blank, shouldn't have any impact on anything.

  12. Inside the Show advanced format options menu, you'll see a number of...yes, format options! You can leave all of them in their default state, but you're welcome to select Check device for bad blocks if you have some concern that the flash drive or USB device you're using may have an issue.

    Choosing 1 pass is just fine in most cases but knock that up to 2 or more if you've had issues with this drive before.

  13. Select START to start the "burning" of the ISO file to the USB device you chose.

    Start button in Rufus on Windows 10

    If you get an Image is too big message, you'll need to use a larger USB device or choose a smaller ISO image.

  14. Read any warning messages and address them appropriately.

    For example, select OK to the WARNING: ALL DATA ON DEVICE 'XYZ' WILL BE DESTROYED message that appears next.

    OK button in "Warning" dialog box

    Take this message seriously! Make sure the flash drive or other USB device is empty or that you're fine with erasing everything on it.

    You might also see a Download required message if Rufus needs some additional files to complete the burn process. Selecting Yes will start that download.

  15. Wait while Rufus properly formats the USB drive so it's bootable, and then copies all the files to the drive that are contained in the ISO image you selected earlier.

    Rufus 3.4 Portable copying ISO files

    The total time to do this depends very much on how large the ISO file is that you're working with. Some small diagnostic tools take under one minute, while larger images (like a 5 GB Windows 11 ISO) could take closer to 20 minutes. Your computer and USB hardware speeds are a big factor here as well.

  16. Once the status at the bottom of the Rufus program window says READY, you can close Rufus and remove the USB drive.

Boot From the USB Drive

Now that the ISO file is properly "burned," you can boot from the USB device and then continue with whatever it is you're using this drive for.

For example, if you've put a memory testing program on a flash drive, you can now boot from that flash drive and test your RAM with it. The same goes for bootable hard drive testing programs, data wipe programs, antivirus tools, etc.

Booting from a USB drive is often as easy as plugging the drive in to any free USB port and then restarting your computer, but it can sometimes be much more complicated. See the tutorial linked above if you need help.

Use the Windows USB/DVD Download Tool

You're more than welcome to use the procedure we've outlined above with Rufus for Windows ISO images, like those you might have downloaded for Windows 11, Windows 10, etc. However, there is a more "official" procedure that uses free software from Microsoft.

We've written complete tutorials on these procedures, which also includes guidance on other aspects of installing Windows from a USB stick. See How to Install Windows 8 From USB or How to Install Windows 7 From USB, depending on the version of Windows you're installing.

Extract ISO Images With a File Compression Program

Rufus, and related ISO-to-USB tools, are great when you need to get some sort of bootable program, or even an entire operating system, onto a USB drive. However, what if you have an ISO image that you want to "burn" to a USB drive that isn't intended to be booted from?

ISO file open in 7-Zip File Manager
ISO file open in 7-Zip File Manager.

In these cases, think of the ISO image you're working with as just any other compressed format, like a ZIP file. Use your favorite file compression program—we often recommend the free 7-Zip tool, but there are many others—to extract the contents of the ISO image directly onto the previously-formatted flash drive. That's it!

  • How do I burn an ISO file to a disc?

    To burn an ISO image file to a DVD, put a blank disc in your drive, right-click the ISO file, and choose the Burn disc image. Follow the prompts to burn the ISO image to the disc.

  • Can I convert a Windows 10 ISO to USB?

    Yes, you can! To make a copy of Windows 10 on a USB flash drive, download and launch the Windows Media Creation tool, select Create installation media and follow the prompts. Then download and install Rufus to complete the process.

  • How would I burn an ISO file to a USB drive on a Mac?

    To create a macOS boot device with a USB flash drive, download the macOS version you want, connect your USB flash drive to your Mac, and enter the appropriate command in Terminal.

  • How do I burn a Linux ISO to USB?

    To burn a Linux ISO to USB, download the Linux ISO file and install the UNetbootin tool. Run UNetbootin and follow the prompts.

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