Windows -- originally codenamed Interface Manager -- was announced by Bill Gates in 1983, but didn't ship until 20 November 1985. Its first incarnation was as a front end for Microsoft's command-line DOS, or Disk Operating System.
Windows 1.0 could only support tiled windows, but had desktop features such as the MS-DOS Executive file manager, Calendar, Cardfile, Notepad, Terminal, Calculator and Clock.
Utilities included RAMDrive, for managing memory cards designed to beat the PC's 640KB memory limit, Clipboard and Print Spooler. There was even a game, Reversi. In a special introductory offer, Windows 1.0 came with Windows Write and Windows Paint and cost $99.