You're here because you have a file that has a file extension ending in .isz. Files with the file extension .isz can only be launched by certain applications. It's possible that .isz files are data files rather than documents or media, which means they're not meant to be viewed at all.

A Zipped ISO disk image file is also called a compressed disk image file, and these Zipped ISO disk image files are integrated with disk image encoding and compression standards proprietary to the EZB Systems UltraISO software. These Zipped ISO disk image files may contain compressed file structures and data similar to the content of an uncompressed disk image file, such as an ISO file, with the only difference being the compression specifications implemented into these Zipped ISO disk image files, commonly done to reduce the size of the file and allow easier and more convenient distribution of the ISO disk image through Web resources or via offline materials like DVDs, CDs and other external data storage devices. AES256 encryption can also be used to implement encryption functionalities into these ISZ files, and protecting an ISZ file against illegitimate access with a unique password is also possible. Dividing these ISZ files into smaller segments for multiple disk storage is also supported by files in the ISZ format, which are affixed with the .isz extension. The DT Soft DAEMON Tools software implements support for these ISZ files.

Launch a .isz file, or any other file on your PC, by double-clicking it. If your file associations are set up correctly, the application that's meant to open your .isz file will open it. It's possible you may need to download or purchase the correct application. It's also possible that you have the correct application on your PC, but .isz files aren't yet associated with it. In this case, when you try to open a .isz file, you can tell Windows which application is the correct one for that file. From then on, opening a  .isz file will open the correct application. Click here to fix .isz file association errors

Be careful not to rename the extension on .isz files, or any other files. This will not change the file type. Only special conversion software can change a file from one file type to another.

A file extension is the set of three or four characters at the end of a filename; in this case, .isz. File extensions tell you what type of file it is, and tell Windows what programs can open it. Windows often associates a default program to each file extension, so that when you double-click the file, the program launches automatically. When that program is no longer on your PC, you can sometimes get an error when you try to open the associated file.