1990: Windows 3.0
Screenshot courtesy of Microsoft.
Windows 3.0, released in 1990 -- and its successor, Windows 3.1, released in 1992 -- offered the first evidence that Windows might become the world's dominant desktop operating system. The interface was revamped, and although it looks awkward and kludgy today, at the time it was widely considered clean and sleek.
Icons were redesigned to use the VGA graphics standard with 16 colors. Memory handling was improved, and enhanced mode was added, which sped up memory access and allowed DOS programs to run in individual virtual machines. Windows 3.0 also allowed Windows applications to use more memory than was available in RAM by swapping RAM temporarily to the hard disk.
Thanks to enhanced mode, DOS programs could be multitasked and run in their own resizable windows for the first time (previously, they had to run full-screen). Windows 3.0 required 640KB of what was called conventional memory and 256KB of extended memory. Version 3.00a of Windows was built to support multimedia, and it supported CD-ROMs for the first time.
Windows 3.0 also included what may be one of the greatest productivity-sappers in the history of computers -- the game of Solitaire.
Windows 3.1 introduced TrueType fonts, for better on-screen reading and higher-quality print output, as well as Object Linking and Embedding, which improved upon DDE for exchanging data between applications. Version 3.11 added support for networking using the dominant networking standard of the time, NetWare.