CD File

What are CD files and how to open them

Are you having problems opening a CD file or are you simply curious about its contents? We're here to explain the properties of these files and provide you with software that can open or handle your CD files.

What is a CD file?

CD files have multiple uses, and CD-i OptImage CD Disk Image is one of them. Read more about the other uses further down the page.

CD-i OptImage CD Disk Image

The .cd file extension is used for an ISO file format developed for older disk image creation programs on Windows PCs. These CD images are in binary form and are called Philips / Optlmage's Master tool files.

The Philips / Optlmage's Master software is an old and outdated disk image creation tool that can be used to generate these .cd files. This software was designed for computers that run on older Microsoft Windows platforms.

These CD files contain directories, sub-directories, and files that are exact copies of the folders and files on the copied CDs.

A .cd file can be mounted as a virtual drive to access and open the files and folders inside the CD copy without having the original CD in the CD drive. These virtual drives are programs that are designed to simulate the functions of optical CD drives, and these are also called CD drive emulators.

How to open CD files

We have identified one CD opener that is compatible with this specific type of CD file.

Programs that open CD-i OptImage CD Disk Image files

Last updated: August 31, 2026

All known file formats using extension .CD

While CD-i OptImage CD Disk Image is a popular type of CD-file, we know of 2 different uses of the .CD file extension. Different software may use files with the same extension for different types of data.

Class Diagram

Class Diagram format files are used by Microsoft Visual Studio to store diagrams that show the structure of a software project's classes, their members (properties, methods, fields), and how they relate (inheritance, association, etc.). These files are edited in Visual Studio's Class Designer, where changes to the diagram surface reflect in source code and vice versa.

The files are written in XML markup. Each file describes layout information (e.g. class box positions, dimensions), type identifiers (linking shapes to code files), stylistic settings (font, visibility of compartments), and relationship definitions. The diagram file does not store implementation details like source code logic - it references existing code files.

Technical details: the root element is <ClassDiagram>, which includes attributes such as MajorVersion, MinorVersion, and MembersFormat. Inside, elements like <Font> specify default appearance, and <Class> elements define each class shape with nested <Position> and <TypeIdentifier> elements.

While we have not verified the apps ourselves yet, our users have suggested four different CD openers which you will find listed below.

Various apps that use files with this extension

These apps are known to open certain types of CD files. Remember, different programs may use CD files for different purposes, so you may need to try out a few of them to be able to open your specific file.

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File.org helps thousands of users every day, and we would love to hear from you if you have additional information about CD file formats, example files, or compatible programs. Please use the links below or email us at submit@file.org to discuss further.