Do you remember Windows 1.0? Chances are, your answer is “no.” When Microsoft released the very first version of Windows nearly 25 years ago, on Nov. 20, 1985, it was late to the game and little used.

Growing up using a PC that ran on Windows 3.1, I don't think it ever occurred to me that there was a Windows 2.1. Or 1.0. That was just Windows, until Windows 95 came around a few years later. But ...

Members of the Windows 1.0 team at their 40-year reunion this week. L-R, kneeling/sitting: Joe Barello, Ed Mills, Tandy Trower, Mark Cliggett, Steve Ballmer (holding a Windows 1.0 screenshot) and Don ...