ISZ File Extension

Zipped ISO Disk Image

File Type isz
Developer EZB Systems
Popularity
4.2 (40 votes)
Application UltraIso
Category Disk Image Files, Compressed Files
Format Zip

What is a ISZ file?

The ISZ file extension is linked to Zipped ISO Disk Image and belongs to the categories of Disk Image Files and Compressed Files, which include 953 files.

The Zipped ISO Disk Image (ISZ) was developed by EZB Systems, which created file format and 2 programs to work with them.

ISZ file support extends to various operating systems, including Mac OS and Windows. To extract a ISZ file, you can choose from 6 programs such as AnyToISO, UltraIso and WinMount.

File Signature

HEX code: 49 73 5A 21. ASCII code: IsZ!.

Windows

Mac OS

How to open a ISZ file?

If you cannot open a ISZ file, it is most often due to missing software. Select a program from the list according to your operating system. Then go to the official website of the program developer, download it, and install it on your device.

Thanks to their popularity, AnyToISO, UltraIso and WinMount are often the go-to programs for managing ISZ files. If you want the most recent release of UltraIso, head over to the EZB Systems site and download the version designed to run on all platforms.

When you finish installing UltraIso, the system will automatically launch ISZ files with it.

Set UltraIso to open ISZ by default

Change default apps on Mac

Right-click or use Control + Left-click on the desired ISZ file to access the file’s context menu;
Choose "Open in Application" and click "Other";
At the bottom of the window, you will see the "Enable" menu. It is already set to the default option, "Recommended Programs";
Within this menu, select "All Programs" and then search for UltraIso. Check the box next to "Always open in app" to make it the default program.

Change a default app in Windows

Start by right-clicking on your ISZ file, then select the "Open with" option and choose "Choose another app" from the menu that appears;
Find the UltraIso application in the pop-up window and select it as your preferred program;
Select the "Always use this application" check box and click "OK" to save your selection as the default application for opening ISZ files.

Easy ISZ Troubleshooting

When facing challenges with ISZ files, simple adjustments in your software can often solve the problem. Find helpful troubleshooting guidance below.

What Causes UltraIso to Crash Frequently?

Insufficient updates for EZB Systems products can cause UltraIso to crash. Be sure to regularly install the latest software updates.

Restarting your computer is often an effective solution to resolve various common problems. Therefore, it is recommended to do so before making any changes to the software configuration.

How can I restore a damaged ISZ file?

Use a recovery program to open the damaged ISZ file, and in the menu, click "Repair" to start the repair operation. Allow the recovery process to complete, which will automatically repair the damaged disk image files.

What are the ways to check if my ISZ file is damaged?

Characteristics of corrupted ISZ disk image files can include:

When opening the file, errors occur or the inability to access its contents;
Editing the archive in UltraIso is hampered by poor overall performance;
UltraIso or other programs stop responding or crash when trying to handle the file;
Unexplained ISZ file size inflation;
Actions performed on the file result in the appearance of error notifications;

How to edit a ISZ file?

To modify ISZ files, you need to install special software that makes it possible to open and edit disk image files. Online ISZ editors are more restricted compared to software designed for Zipped ISO Disk Image.

Best ISZ Editor Software in 2026

After analyzing the criteria, we have created a list of ISZ editors available for use.

ISZ Editor Software	Developer	Platforms	Overall Rating
UltraIso	EZB Systems	Windows	4.4 out of 5 (42 reviews)

Convert files to and from ISZ

If working with a ISZ file is challenging, one solution is to convert it to formats like ISO, DMG, NRG, MDF, DAA or other supported formats.

After converting a ISZ file, some capabilities may be limited, but you can often convert it back to the original format.

Offline software options such as Alcohol 120% guarantee lossless conversion of ISZ files.