Windows 1.0 is a 16-bit  graphical operating environment that was released on November 20th 1985.[1]  It was Microsoft's first attempt to implement a multi-tasking  graphical user interface-based operating environment on the PC  platform. Windows 1.0 was the first version of Windows launched. It was succeeded by Windows 2.0.

Link to full article: http://www.securityfreak.info/entertainment/windows-1-0-introduction-history

This is the download link for Windows 1.0!
http://cip5p52lqmufd3kc.onion/file/53N876

To download the file you are going to need the Tor browser.

You can know more about it here:
http://www.securityfreak.info/security/using-and-testing-tor-browser-for-the-first-time/

Enjoy!