What are ISO files and how do I use them?

An ISO image is an archive file (also known as a disc image) of an optical disc in a format defined by the International Organization for Standardization (ISO). This format is supported by many software vendors. ISO image files typically have a file extension of .iso.

Article first published as What Is An ISO File And How Do I Use Them? on Technorati.

Wikipedia defines an ISO file as:

An ISO image is an archive file (also known as a disc image) of an optical disc in a format defined by the International Organization for Standardization (ISO). This format is supported by many software vendors. ISO image files typically have a file extension of .iso.

To expand on that definition further, an .iso image is much like a .zip file. You can think of it as a container that holds all the files and folders contained on a CD or DVD but unlike a .zip file an ISO is not compressed. ISO files are useful for keeping backups of CD’s and DVD’s and for storing the contents of CD’s or DVD’s on portable hard-drives or uploading and downloading them on the internet.

How to use an .iso file

When using an ISO file you have three options, you can either:

  • Copy it to a CD or DVD
  • Mount it on to a ‘Virtual CD/DVD Drive’
  • Extract the contents of it to your hard-drive

How to copy an .iso image to a CD or DVD

Starting at the top of the list I will first explain how to create a CD/DVD from an ISO. Firstly you will need a program that is able to process and burn the image to a disc. For this I would not look past a neat piece of freeware called ImgBurn. It is completely ad and spyware free and I have been using it myself for a long time now.

During the install there is a dialogue which will ask you if you want to install the Ask toolbar, I generally untick the agreement tick box at this point and continue with the installation. ImgBurn will be installed without any toolbar junk.

Using ImgBurn to create a CD/DVD from an .iso image

Step 1

Start by opening ImgBurn and selecting the ‘Write image file to disc‘ option (Pictured Left). Pretty simple so far isn’t it?

Step 2

In the next window you will need to click on the little folder icon with the magnifying glass on it. If you don’t know what I am talking about just click on the image to the right for a full-size screenshot.

Step 3

The next part is very straight-forward but for consistency I have included a screenshot for that too. Simply locate and select your .iso file in the Open file dialogue and click ‘Open’.

Step 4

The final step is to press the big ‘Image to Disc’ button at the bottom of the window and the burn process will begin! If the button is ‘greyed out’ check that you have blank CD or DVD in your drive. Wait for the disc drive to finish recording to the disc and you are all done.

How to mount an .iso image to a Virtual CD/DVD Drive

If you do not need a physical copy of the data included in the .iso file or you have ran out of writeable CD’s or DVD’s you can use a program called Daemon Tools (yes, it’s free for personal use) to act as a ‘Virtual CD/DVD’ drive.  Once installed, a new CD/DVD drive will appear on your computer and will operate just like a normal CD/DVD drive but instead of reading physical discs it will read .iso files (and other image file formats) and run them as if you were reading it from a physical disc.

Rather than ejecting the CD tray and inserting a disc as you would with a conventional drive you will instead be ‘mounting’ .iso image files to the virtual drive in order to read them. Read on to find out just how to do it.

So if you have not done so already download and install Daemon Tools. Rest assured it is completely ad and spyware free and very lightweight, meaning it will not take up much memory or hard-drive space on your computer. After the installation is complete you may need to reboot your computer for the changes to take effect.

Using Daemon Tools to read an .iso image

Step 1 – The Second to Last Step

To begin open up Daemon Tools. In the bottom part of the window you should see an icon depicting a drive. In my case it is called ‘Device 0: [G:]‘. You will need to right click on this icon and select the ‘Mount‘ option. (See image left).

Step 2

Again, locate your .iso file and open it and that is all there is to it! You have now mounted your .iso image file to the virtual drive, depending on your Windows settings you may receive an Autoplay menu or you can access it as you would access any other drive on your computer, whether that be via ‘My Computer’ in Windows or ‘Windows Explorer’. In my case I would access my virtual drive via the G: drive but the drive letter may vary from PC to PC.

To unmount the image you can simply open up Daemon Tools again, right click on the virtual drive as in step 1 and click on ‘Unmount’.

How to extract the contents of an .iso file to your computer

Although I don’t recommend using this method it may be useful in some instances so I will take the time to explain the process of extracting the contents of an .iso image file to your PC. As in the last two methods you will need some freeware to make it possible for this I suggest WinRAR. Select the correct version of WinRAR from the download page. If you are running a Windows based operating system and are unsure about which version to download just start with the x86 version.

Using WinRAR to extract an .iso image to your computer

Step One

Once you have installed WinRAR you will need to open it up and from the ‘File‘ menu select ‘Open Archive‘. Locate and open your .iso file from the dialogue box.

Step Two

Once you have opened your .iso file you will need to extract it’s contents to a folder somewhere on your computer. To do this click on the ‘Extract To‘ button at the top. Choose file destination file path to which you want the contents of the .iso file to be extracted to and press ‘OK’.

The time it takes to extract the file will depend on the size of the .iso file you are extracting and the speed of your computer but be patient in any case as it can take up to 5 – 10 minutes for larger files.


That is all you really need to know for dealing with .iso files! Hopefully this has been helpful and you are now able to fully understand how useful this file format can be.

As usual if you have any questions ask me in the comments below and I will do my best to answer them as quickly as I can.

Thanks for reading.

2 thoughts on “What are ISO files and how do I use them?”

  1. Your help has been great ! I am new to ISO files.
    More help ? I bought and downloaded office outlook 2003 and I went thru all the steps you showed.
    I extracted the file to my desktop but I still can’t figure out how to open and use it.

    I bought it from PCDeal4U.

  2. hello i was wondering if you were able to answer a question i have. say i have an iso disk copy for a game but i downloaded the game from the xbox 360 marketplace. is it still possible to use an iso or do i actually have to have a hard copy first. thank for your time and an answer would be much appreciated.

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