Convert IMZ to ISO

A legacy DOS or other floppy-disk image may need conversion when the receiving emulator, virtual machine, burning utility, or archive accepts ISO but not IMZ. Because IMZ and ISO describe different media types, the reliable method extracts the floppy contents and builds a new optical-disc image.

What the IMZ format is

IMZ is a compressed floppy-disk image format associated mainly with WinImage. It stores the sectors and filesystem of a floppy disk in a compressed file and is used for DOS disks, boot disks, installation media, emulator collections, and legacy software archives.

IMZ normally represents floppy media, including its filesystem and disk geometry. It is not an ISO and cannot be treated as an optical-disc image without changing the image structure.

What the ISO format is

ISO is an optical-disc image format used for CDs, DVDs, virtual optical drives, burning software, and software distribution. ISO 9660 provides the standard directory structure; Joliet and Rock Ridge extensions add longer filenames and additional metadata for compatible systems.

ISO files are widely supported by Windows, Linux, macOS, virtual machines, emulators, mounting tools, and disc-authoring software. An ISO built from an IMZ is useful for transferring the floppy's files as one mountable image, but it does not preserve floppy sectors, geometry, bad sectors, or copy-protection behavior.

How to convert IMZ to ISO

1. Install WinImage from its official website and open the IMZ with File → Open.
2. Extract the complete image to a temporary directory. Preserve hidden and system files, especially when the source is a boot disk. Do not copy only the files visible in a normal file browser.
3. Use an ISO authoring program such as AnyBurn or ImgBurn. In AnyBurn, choose Create image file from files/folders. In ImgBurn, choose Create image file from files/folders.
4. Add the extracted directory's contents, choose .iso as the output filename, and create the image. Select ISO 9660 with Joliet when compatibility with current operating systems and older tools is required.
5. Mount the ISO or open it with an archive utility and check that all expected files, directories, and filename forms are present. Retain the original IMZ as the source image.

AnyToISO can also create an ISO from the extracted directory. Some versions advertise direct IMZ support, but extraction followed by ISO authoring is easier to verify and avoids assuming that a direct conversion preserves floppy-specific data.

On Linux or macOS, xorriso can create the ISO after extraction:

xorriso -as mkisofs -J -R -o output.iso extracted/

There is no dependable general-purpose online IMZ-to-ISO service to recommend. Many online converters do not recognize WinImage's compressed floppy format, and uploading a disk image can disclose licensed software, personal files, or archived data.

Bootability and compatibility

Adding boot files to an ISO does not make it bootable. A bootable CD or DVD requires an El Torito boot entry and a suitable boot image. If the original IMZ is a boot disk, first save or export it from WinImage as an uncompressed floppy image such as .IMA or .IMG, then configure the authoring program's bootable-disc option with that image if the target firmware and software support floppy emulation.

A floppy boot sector cannot always be reused unchanged as an optical-disc boot image. Test the finished ISO in the intended emulator or virtual machine rather than assuming that a successful file listing proves bootability.

If the recipient expects a floppy image, requires exact sector layout, or depends on unusual geometry, bad sectors, copy protection, or low-level boot behavior, do not convert it to ISO. Keep the IMZ, or convert it only to an appropriate uncompressed floppy-image format such as .IMA or .IMG.