Can Windows open ISO files without software?

Yes. Windows 8 and every version since can mount an ISO natively: right-click the file and choose Mount, and it appears as a drive. Third-party tools are only needed for extraction to a folder or for creating bootable USB media.

How do I make a bootable USB from an ISO?

Use Rufus or Ventoy on Windows, or balenaEtcher on any platform. These write the image to the drive at sector level. Simply copying the ISO file onto the USB stick will not boot.

File extensions

How to open a .iso file

ISO disc image · Disc image

An .iso file is a complete disc image. Windows 8 and later mount it with a right-click, and macOS mounts it on double-click. No software is needed just to see what is inside.

What a .iso file actually is

An ISO is a byte-for-byte copy of an optical disc, named after the ISO 9660 filesystem. It is how operating systems, installers and archived media are distributed.

Because it is a filesystem image rather than an archive, mounting it is the natural operation: the contents appear as a drive letter or volume, exactly as if you had inserted the disc.

Why it will not open

Usually nothing is wrong. People assume an ISO needs special software because that was true on Windows 7, where mounting required a third-party tool. From Windows 8 onward the capability is built in and largely undiscovered.

Step by step

Windows

01Right-click the .iso file and choose "Mount". It appears as a new drive in File Explorer.
02Open that drive and use the files as normal.
03When you are finished, right-click the drive and choose "Eject".
04To extract rather than mount, right-click and open with 7-Zip, which unpacks the contents to a folder.
05To put it on a USB stick as bootable media, use Rufus or Ventoy. Copying the file across does not work.

macOS

01Double-click the .iso. It mounts and appears on the desktop and in Finder.
02Eject it from Finder when you are done.
03Note that some Windows installer ISOs use a filesystem macOS will not mount; extract them with Keka instead.

What usually goes wrong

Copying an ISO to a USB stick does not make it bootable

Dragging the file onto a USB drive gives you a USB drive with a file on it. Creating bootable media means writing the image sector by sector, which is what Rufus, Ventoy and balenaEtcher do.

Programs that open .iso

Our pick, in order. Every one links to the publisher's official download URL and the SHA-256 hash of the installer, so you can check the file before you run it.

Also registers .iso in its manifest

Taken straight from publisher manifests. Some of these handle the format for a narrow purpose rather than as their main job.

Common questions

Can Windows open ISO files without software?: Yes. Windows 8 and every version since can mount an ISO natively: right-click the file and choose Mount, and it appears as a drive. Third-party tools are only needed for extraction to a folder or for creating bootable USB media.
How do I make a bootable USB from an ISO?: Use Rufus or Ventoy on Windows, or balenaEtcher on any platform. These write the image to the drive at sector level. Simply copying the ISO file onto the USB stick will not boot.