Believe it or not (depending how old you are will bring back memories), but Microsoft Windows started it’s life in the 80’s.
In November of 1983, Bill Gates showed IBM his new operating system, Windows. It went down like a lead balloon, but Bill realised that a proper GUI based operating system would be the way of the future.
Microsoft Windows 1.0 was released on November 20, 1985. It wasn’t a complete operating system like today as it was an extension of MS-DOS (which was released in 1981), the ‘command line’ or text based operating system.
From 1985, the selling details were as follows:
Hardware Requirements: 80386 CPU, 256KB RAM, 1MB Storage
Media Size: five 360KB 5.25″ floppy disks
Windows 1.0 ran a shell program known as MS-DOS Executive. Other supplied programs are Calculator, Calendar, Cardfile, Clipboard viewer, Clock, Control Panel, Notepad, Paint, Reversi, Terminal, and Write.
Windows 1.0 did not allow overlapping windows, due to Apple Computer owning this feature. Instead all windows were tiled. Only dialog boxes could appear over other windows.
Windows 1.0 executables, while having the same .exe extension and initial file header as MS-DOS programs, did not contain the so-called MS-DOS stub which prints the “This program requires Microsoft Windows” message and exits when the program is run outside of Windows. Instead, the file header was formatted in such a way as to make DOS reject the executable with a “program too large to fit in memory” error message.
From the beginning, Windows was intended to multitask programs (although this originally only applied to native applications and for many versions the multitasking was co-operative, rather than preemptive), so Windows programs always had their own menu bar rather than switching a single menu bar at the top of the screen like Apple Macintoshes did.
For a more detailed view on Windows 1.0, have a read here.