What is an ISO file? How to open an ISO file on Windows?

If you are trying to install Windows on your computer, you may have come across ISO files. These files magically load up an entire OS and other software onto your computer. But what exactly is an ISO file? How do you open an ISO file on Windows? We answer your queries in this article.

What is an ISO file?

An ISO file is an optical disc image file. The “ISO” in the name comes from the ISO 9660 file system that was used in erstwhile CD-ROMs.

An ISO file is thus a disk image and is often referred to as an ISO image too. It is an archive file that is the replica of everything that would be written on an optical disc, like a CD, DVD, or even Blu-ray, including the file system itself.

You can think of an ISO file as the digital format of a physical CD or DVD. They make it easier to handle CD/DVD data without needing to handle one physically.

ISO files often come with a .iso file extension but can also take the .img extension.

In the past, ISO files were burnt onto CDs and DVDs. But as CDs and DVDs went out of fashion, we now burn them onto USB drives or, even better, run them directly on the OS by mounting a virtual disc with this ISO.

What are ISO files used for?

ISO files are most commonly used to create backups of physical CDs, DVDs, and Blu-rays. They are also used to digitally distribute file sets (like large programs and operating systems) that were previously intended to be distributed by physical CDs and the like.

If you have an ISO file on your computer, you can decide whether to burn it onto a CD/DVD/Blu-ray and then run it on any computer or directly use the ISO file.

Most commonly, you would have seen Windows installation guides talk about using a Windows ISO to install the OS whenever a new Windows OS is released. Linux distributions also come in ISO formats.

Emulators are another everyday use case for ISO files. Emulators like Dolphin Emulator and PCSX2 use ISO files to emulate Wii, GameCube, and PlayStation 2 games.

How to extract, open, install, or mount an ISO file

Working with ISO files is very easy on Windows. The OS lets you easily mount ISO files to open them and even burn ISO files to USB, and you can follow our linked guides to learn how to do the same. When you need to extract the contents of an ISO file for inspection, you need an external utility.

You will need a program like WinRAR or 7-Zip to extract an ISO file on Windows. We recommend using 7-Zip as it is free and open source. Follow these steps:

• Download and install 7-Zip on your Windows computer.
• Locate where your ISO file is. If you have downloaded the ISO file, it will be in your Downloads folder.
• Right-click on the ISO file, and click 7-Zip > Open archive.

• You can now see the contents of the ISO file.
• If you want to extract files, select the files, and click on the Extract button in the top navigation bar.

• Check the destination where you want to extract the files and click OK.

• The ISO will be extracted to your destination folder.

7-Zip usually associates itself with the .iso file format, so you won’t need to right-click on your ISO file in most cases. You can simply double-click on it to open the ISO file and view its contents. However, Windows 11 also likes to associate with ISO files to allow easy installation, so we prefer taking the longer route since it always works.

Note that large ISO files may take a while to open and extract.

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