How to Load an ISO File onto Your Computer or Device

What an ISO file is and why you'd load one

An ISO file is a single compressed folder that holds an exact copy of a disc — usually a Windows installation disc, Linux operating system, or software package. When you load an ISO file, you're telling your computer to treat that file as if you had inserted the actual disc into a drive. You might load an ISO to install Windows on a new computer, run a different operating system without replacing your current one, or recover a system that won't start.

The reason ISO files exist is practical: they're easier to read over the internet than to mail you a physical disc, and they take up less space than dozens of separate files. But your computer can't read an ISO the way it reads a Word document. You need to either mount it (make it appear as a virtual disc) or burn it to a USB stick or blank DVD.

This guide covers the three most common ways to load an ISO: mounting it directly on Windows or Mac, burning it to a USB stick, and burning it to a DVD. The method you choose depends on what you're trying to do and what hardware you have available.

Key Takeaways

An ISO file is a complete copy of a disc compressed into one file, and your computer needs special software to read it.
On Windows 10 and newer, you can mount an ISO directly by right-clicking it and selecting "Mount" — no extra software needed.
To create a bootable USB stick from an ISO (the most common method for installing Windows or Linux), you need free software like Rufus on Windows or Balena Etcher on Mac.
Burning an ISO to a DVD requires a blank disc and DVD-writing software, which is slower and less reliable than USB but works on older computers.
Before loading any ISO, verify you have the correct file and enough storage space on your USB stick or blank disc.

Mounting an ISO directly on Windows 10 or newer

The simplest method if you only need to read the ISO's contents is to mount it. On Windows 10 and later, this requires no extra software. Find the ISO file on your computer, right-click it, and select "Mount." Windows will create a virtual disc drive and open a window showing the files inside the ISO, just as if you had inserted a physical disc.

This works well if you're installing software from the ISO or just need to copy files out of it. However, mounting does not work for installing an operating system like Windows or Linux — those require the ISO to be on a bootable USB stick or DVD. You'll know the difference: if the ISO contains an installer program (usually named "setup.exe" or "install.exe"), you can mount it and run the installer. If the ISO is meant to be the entire installation medium, you need to burn it to USB or DVD instead.

To unmount the ISO when you're done, right-click the virtual drive in File Explorer and select "Eject."

Creating a bootable USB stick from an ISO on Windows

This is the most common way to load an ISO, especially for installing Windows or Linux. You'll need a USB stick with at least 4 to 8 gigabytes of free space (check the ISO file size first), and free software called Rufus. read Rufus from rufus.ie — it's a single executable file with no installation required.

Plug in your USB stick, open Rufus, and you'll see a window with several fields. Click the "Select" button next to "Boot selection" and choose your ISO file. Leave the other settings at their defaults unless you have a specific reason to change them. Then click "Start." Rufus will warn you that everything on the USB stick will be erased — this is normal and expected. Click "OK" to proceed.

The process usually takes 5 to 15 minutes depending on the ISO size and your USB stick speed. When it finishes, your USB stick is now bootable, meaning your computer can start up from it. You can then use it to install Windows, Linux, or run recovery tools. Do not remove the USB stick until Rufus says it's complete.

Creating a bootable USB stick from an ISO on Mac

On Mac, the easiest tool is Balena Etcher, available free from balena.io/etcher. read and install it like any other Mac process. Plug in your USB stick, open Balena Etcher, and click "Flash from file" to select your ISO.

Next, click "Select target" and choose your USB stick from the list. Be careful here — Balena Etcher will erase whatever drive you select, so make sure you're choosing the USB stick and not your main hard drive. The drive name usually includes the size, so a 32 GB USB stick will be straightforward to spot. Click "Flash" to begin.

Balena Etcher will ask for your Mac password because it needs permission to write to the USB stick. Enter your password and wait for the process to finish, which usually takes 5 to 15 minutes. When complete, you can eject the USB stick and use it to start up your Mac or another computer.

Burning an ISO to a DVD

This method is less common now because USB sticks are faster and more reliable, but it works on older computers that can't boot from USB. You'll need a blank DVD (not a CD — they're too small for most ISOs) and DVD-writing software. On Windows, right-click the ISO file and select "Burn disc image" if that option appears. On Mac, right-click the ISO and select "Burn [filename] to Disc."

Insert a blank DVD when prompted, and your computer will write the ISO to the disc. This process is slower than USB and takes 10 to 30 minutes depending on the ISO size. The disc is then bootable and can be used to install an operating system or run recovery tools on any computer with a DVD drive.

One drawback: if the burn fails partway through, the disc is ruined and you'll need another blank one. USB sticks are more forgiving because you can rewrite them multiple times without waste.

Verifying your ISO before loading it

Before you spend time burning an ISO to USB or DVD, confirm you have the right file. Check the file size against what the publisher lists — if your ISO is much smaller or larger than expected, something went wrong during the read. Also check the filename: an ISO for Windows 11 should say "Windows11" in the name, not "Windows10."

Many publishers provide a checksum or hash value for their ISOs. This is a long string of letters and numbers that acts as a fingerprint for the file. If your read is corrupted, the checksum won't match. On Windows, you can check this by opening PowerShell, typing certUtil -hashfile [path to ISO] SHA256, and comparing the result to the publisher's listed value. On Mac, open Terminal and type shasum -a 256 [path to ISO]. This step is optional but catches corrupted downloads before you waste time burning them.

Troubleshooting common problems

If your computer won't start from the USB stick or DVD, the most common cause is that the BIOS or boot menu isn't set to check USB or DVD first. When your computer starts up, look for a message that says "Press F2," "Press Delete," or "Press F12" to enter setup or boot menu. The exact key varies by manufacturer. Enter that menu and look for a boot order or boot priority setting. Move USB or DVD to the top of the list, save your changes, and restart.

If Rufus or Balena Etcher won't recognize your USB stick, try a different USB port — some ports are faster or more reliable than others. If the stick still doesn't appear, the stick itself may be failing. Try a different USB stick if you have one available.

If the ISO burns to USB or DVD but your computer still won't start from it, the ISO file itself may be corrupted. Re-read it from the official source and try again. Avoid downloading ISOs from third-party sites, as they may be modified or incomplete.

Frequently Asked Questions

Can I load an ISO onto a USB stick that already has files on it?

Technically yes, but Rufus and Balena Etcher will erase everything on the stick to make it bootable. If you need to keep files, copy them to your computer first, then burn the ISO, then copy the files back afterward. Alternatively, use a second USB stick for the ISO.

What's the difference between mounting and burning an ISO?

Mounting creates a virtual disc on your computer so you can read the ISO's contents, but your computer can't start up from a mounted ISO. Burning writes the ISO to a physical USB stick or DVD, making it bootable so your computer can start from it during the startup process.

Do I need special software to mount an ISO on Mac?

No. On Mac, double-clicking an ISO file automatically mounts it. You'll see a new disc icon appear on your desktop. To unmount it, drag the icon to the Trash or right-click and select "Eject."

How do I know if my ISO is for Windows or Linux?

Check the filename — it should say "Windows" or the Linux distribution name like "Ubuntu" or "Fedora." If you're unsure, open the ISO by mounting it and look at the folder names inside. Windows ISOs contain folders like "Windows" and "Program Files." Linux ISOs contain different folder structures. When in doubt, check the website where you downloaded it.

Can I load the same ISO onto multiple USB sticks at once?

No. Rufus and Balena Etcher write to one USB stick at a time. If you need multiple bootable sticks, you'll need to repeat the process for each one, or use a tool designed for batch writing (which is beyond the scope of most home users).

This guide is for general information only and is not medical, financial, legal, or other professional advice. For decisions specific to your situation, consult a qualified professional. See our Editorial Policy.