1987: Windows 2.0
Screenshot courtesy of Microsoft.
Windows 2.0 was released in the late fall of 1987, two years after the debut of Windows 1.0. New features in Version 2.0 included the ability to overlap application windows and improved memory use. Also new: Dynamic Data Exchange (DDE), which allowed Windows applications to automatically share and update data. For example, DDE allowed information in an Excel spreadsheet to be automatically updated when data in another Excel spreadsheet was changed.
Windows 2.0 also included expanded system requirements: It needed 512KB or more of memory and required DOS 3.0. A later version, Windows 2.11, would require the use of a hard disk for Windows for the first time.
With Version 2.0, more applications written for Windows began to appear, including Microsoft Excel and Word. Aldus' PageMaker, originally written for the Mac, was also ported to Windows.
Windows 2.0 was notable for another reason as well -- on March 17, 1988, Apple Computer sued Microsoft, claiming that the look and feel of the Macintosh operating system was covered by copyright, and that Windows 2.0 violated that copyright. (Several years later, the case was resolved in Microsoft's favor.)