How To Extract ISO Images to a USB Thumb Drive

So you’ve downloaded an operating system off the Internet.  Now what?  How does it work?  What do you do?  Well fortunately, I am here today to answer part of some of those questions.  Yay me!

Congratulations, you’ve downloaded an operating system.  Unfortunately, operating systems usually come as a meaningless file that doesn’t seem to do anything.  That file is known as an ISO image, and to use it, you must do one of several things.


Your first option is to “mount” the ISO image into a virtual machine.  This is great, and very useful for temporarily testing out new Linux distributions.  But restricts you to using virtual machines.

Your second option, and the one most operating system websites advocate, is to burn your ISO image to a disc such as a CD or DVD.  This is certainly a valid option, and in some situations preferable.  However, burning to a CD or DVD uses up a perfectly good CD or DVD.  Instead of doing that every time we download an operating system, which is often, we’re geeks, we can use a simpler, cheaper, and less permanent solution.  The much vaunted third option.

The third option, or, more descriptively, extracting the ISO to a bootable USB thumb drive offers several benefits.  The first, speed.  If done with a fast computer and USB thumb drive, installing operating systems is speedier.  Modern thumb drives are much faster than CDs and DVDs.

Another benefit is the non-permanence.  Thumb drives are rewritable.  When you’re done with an operating system, simply overwrite it.  Yes, I hear you out there protesting.  It’s true, there are rewritable CDs and DVDs, but they aren’t all that popular and are usually more work and more expensive than they’re worth.  Thumb drives are cheap and more easily manipulated.  Today, this third option is the focus.

Prepping the Playing Field

I know, it’s not a great sports metaphor.  I’m not a metaphorist.  Is that a word?  Metaphorist?  One who metaphors?  No?  Damn.  Well, I’m using it anyway!

Tools.  We need to gather some tools before continuing.  That’s what the metaphor was trying to convey.  Tools.  Here is a list of tools you’ll need… to prepare the playing field.

  1. Empty USB thumb drive that is large enough.
  2. The operating system file. This is the ISO image we mentioned before.
  3. UNetbootin installed on a computer.

1.  Empty USB Thumb Drive

There are hundreds, if not thousands of USB thumb drives on the market this very moment that are adequate.  For this task, the most important aspect of your thumb drive is its size, followed by its speed.


Modern operating systems are usually large.  Your thumb drive needs a bit more space than the downloaded file size.  For instance, one of the current releases of Linux Mint is 915 MB which is just a tad under 1 GB.  Therefore, the smallest size of thumb drive available, that can hold the Linux Mint installer, is 1 GB.  Microsoft’s Windows 8 is 3.4 GB.  The smallest thumb drive available capable of holding the Windows 8 installer is 4 GB.


Your USB thumb drive will also be the speed bottleneck when installing your operating system.  If you use a slow thumb drive, or have an older computer that reads USB thumb drives slowly, the install will progress slowly.  A fast thumb drive, combined with a recent computer will speed up the process significantly.


If you do not already have a thumb drive that is adequate, or simply want to upgrade to a new one, we highly recommend the following option.  It is one of the fastest thumb drives on the market, is large enough to hold future operating systems for years to come, and is competitively priced.

Patriot 32GB Supersonic Rage Series USB 3.0 Flash Drive With Up To 180MB/sec- PEF32GSRUSB (Personal Computers)

List Price: $17.99 USD
New From: $15.97 USD In Stock
Used from: Out of Stock

If cost is a concern, you can cheaply obtain a more modest thumb drive that should still suit your needs.  Here is an excellent choice.  It’s not as big and isn’t as fast, but it is still very good.

Kingston Digital DataTraveler SE9 8GB USB 2.0 (DTSE9H/8GBZET) (Personal Computers)

List Price: Price Not Listed
New From: 0 Out of Stock
Used from: Out of Stock


2.  The Operating System File

Most Linux distributions come in the form of an ISO image.  It is a single file with a .iso file extension.  You will want to have this file handy as you are going to feed it into the UNetbootin program obtained in the next step.

Check out our article, How To Get Linux, for more information.


3.  UNetbootin Installed on Your Computer

UNetbootin is a free utility available at the following website:  It will do all the necessary work required to load your operating system file on the USB thumb drive, and to make it bootable.

UNetbootin is available for Windows, Linux, and Mac OS X.  It is primarily used for installing Linux Distributions, and that is how it is marketed, but it works for other operating systems as well.


Play Ball!

Yes.  Yes.  The sports metaphors suck.  Just go with it and move on please.  Thank you!  The point is we can start the process now that the tools are assembled.

Plug in your USB thumb drive and open UNetbootin.  You will be presented with a window like this:

UNetbootin opening screen.


Make sure at the bottom, where it says “Type: USB Drive”, your USB thumb drive is selected.  During this process, the thumb drive’s contents will be erased, so back everything up before continuing, and ensure you have selected the correct drive!


Now, select the “Diskimage” button, then click the ellipsis (“…”) button.  Find your ISO image in the file browser that opens and select it.

Click “OK.”  A new window will open with a progress bar.

Unetbootin progress screen.


Let UNetbootin do its thing.  It may take several minutes.  Once finished, you will see this:

UNetbootin finish screen.


If you want to install your operating system on the computer you’re using for this, click “Reboot Now.”  If you want to wait, or use a different computer, simply click “Exit.”


Bottom of the 9th

YES!  More sports metaphors that don’t fit!  The point is we’re almost done.  Geez!

There is a good chance that your computer is not setup to boot from a USB thumb drive by default.  You will likely have to take action during your computer’s startup procedure.  Unfortunately, the steps you must take are not universal.  If you can, use your favorite search engine to find instructions on how to boot from USB for your specific computer.

If your search engine isn’t helping, then there is an excellent generic guide you can find here:  The steps probably won’t be exactly the same, but it guides you along the correct path.  If you are unable to do this, let us know in the comments and I, or someone else, will try and help you.


Once your computer is setup to boot from USB, make sure your thumb drive is plugged in and start/restart your computer.  Your operating system installer should start right up.



And there you have it.  By the way, we are curious.  What distribution did you download?  Did these instructions work for you?  Do you hate sports metaphors?  To answer these questions, scroll down.  There is a comments box right down there.


Written By

John is a sailing instructor and mechanical engineering student who happens to be a computer geek. To find more information about John, visit his website or find him on social media by clicking on the icons below.

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