Microsoft maked the source code for MS-DOS and Word for Windows available to the public

Last Updated on February 17, 2024 by Michael Morten Sonne


This is only for Digital Time Capsules about this topic!

Unlocking Digital Time Capsules

In a noteworthy step towards preserving computing history, Microsoft (yes I know it´s some years ago) unearthed and shared the source code for early versions of MS-DOS and Word for Windows. Collaborating with the Computer History Museum, the tech giant is allowing the public unprecedented access to these foundational pieces of software, shedding light on the roots of personal computing.

The significant historical software programs MS-DOS 1.1 and 2.0, along with Microsoft Word for Windows 1.1a. is maked available. This initiative aims to empower future generations of technologists with a deep understanding of the origins of personal computing during the 1980s.

Here is the chkdsk command

In MS-DOS, CHKDSK (Check Disk) was a command-line utility used to check the integrity of a disk drive and fix any errors it found. It scanned the file system for issues, such as bad sectors, and attempted to repair them. CHKDSK was commonly used to maintain the health and stability of storage devices in early Microsoft operating systems like MS-DOS.

The Commandline tool in newer Windows editions is still named CHKDSK – check it! 😉

More to the history

The journey into MS-DOS and Word for Windows harks back to 1980 when IBM approached Microsoft for a project codenamed “Chess.” This collaboration marked a pivotal moment in personal computing history, as Microsoft transitioned from providing the BASIC language interpreter for IBM to creating an operating system. The foundation for PC-DOS and MS-DOS emerged from the licensing of an operating system from Seattle Computer Products.

Bill Gates, in an interview with David Bunnell, shared insights into the early days of this collaboration. Microsoft’s staff dedicated substantial time and effort to the IBM project, creating a unique relationship that contributed to significant advancements in the personal computer industry.

Following the MS-DOS era, Microsoft introduced the first DOS-based version of Microsoft Word in 1983, designed for mouse interaction – yes you read right! 😂

The 1989 release of Word for Windows marked a turning point, becoming a blockbuster for Microsoft and dominating the worldwide word-processing market within four years.

Reflecting on the humble beginnings, Microsoft highlighted the growth from under 100 employees and MS-DOS with less than 300KB of source code to a company that has sold over hundred of million licenses of Windows and boasts over billion(s) users of Microsoft Office and is over 200.000 employees worldwide and the newly rebranded Microsoft Entra ID (ex-Azure AD) has more than 610 million monthly active users and the steady growth of Enterprise Mobility and Security seats to 259 million monthly active users (October 2023).

Etc. Microsoft 365 tenants share a single large logical infrastructure composed of hundreds of thousands of servers spread across multiple Microsoft data centers worldwide (Microsoft 365 and Azure) spans well over 200 data centers!.

The journey from modest origins to global influence is a testament to Microsoft’s evolution.

As these pivotal pieces of source code are made available to the community, they stand as a tribute to the company’s roots and a reminder that great things often start from humble beginnings, echoing the trajectory of MS-DOS and Word for Windows.

The source code

The source code for MS-DOS and Word for Windows that Microsoft released. MS-DOS, for example, was originally developed by Microsoft for IBM’s personal computer (PC). In the case of MS-DOS, Microsoft initially provided the BASIC language interpreter for IBM, but when IBM needed an operating system for their PC, Microsoft licensed an operating system from Seattle Computer Products. This operating system, known as QDOS (Quick and Dirty Operating System), was then modified by Microsoft to become the foundation for PC-DOS and MS-DOS.


Part of MS-DOS 2.0 – Diskcopy code

Word for Windows

For Word for Windows, Microsoft developed the software in-house. The source code represents the programming instructions, algorithms, and logic that were written by Microsoft’s engineers to create these iconic software products. It’s a glimpse into the historical development of these software systems and the technology of the time.

Some parts of MS Word – here Dialog function for “Save As”

The language for MS-DOS is Assembly.

The language for Word for Windows is C and Assembly.


    I have it cloned at my GitHub profile where you can find a copy of it 😊

    Original publiched from Microsoft here:


    This move by Microsoft not only serves as a nostalgic trip down memory lane for those who fondly remember the ‘C:>’ command prompt but also as a valuable resource for students of computer science and programming history. The availability of these historical artifacts fosters a deeper understanding of the technological evolution that has shaped our modern digital landscape.

    The decision to make the source code available to the public underscores a shift in the tech giant’s approach towards transparency and preservation of computing history. It’s a reminder that even in the fast-paced world of technology, there’s value in reflecting on the roots of innovation and the journey that has brought us to where we are today.

    So, whether you’re a seasoned developer looking to uncover the secrets of MS-DOS or a curious mind eager to explore the inner workings of Word for Windows, Microsoft’s decision to share these digital relics is an invitation to embark on a historical journey, celebrating the roots of personal computing and the code that started it all.

    Thank you for taking the time to visit my blog. Kindly share it with others if you find it helpful for them! 😉🔐👍

    Stay tuned for the new post about something cool! 🥳


    Microsoft makes source code for MS-DOS and Word for Windows available to public – The Official Microsoft Blog

    Computer History Museum License Agreement | Microsoft DOS V1.1 and V2.0 – CHM

    Microsoft Research License Agreement | Microsoft Word for Windows version 1.1a – CHM (

    Leave a Reply

    Your email address will not be published. Required fields are marked *

    This site uses Akismet to reduce spam. Learn how your comment data is processed.

    Previous Article

    Entra ID - Global Secure Access Client - What it is about - Part 1

    Next Article

    Microsoft Defender XDR - Offboarding scripts will now expire in 3 days and not 30 days

    Related Posts

    Discover more from Sonne´s Cloud

    Subscribe now to keep reading and get access to the full archive 🤝🧑‍💻

    Join 15 other subscribers