The first version of Windows was released in 1985. It ran on top of a MS-DOS installation and provided a graphical interface that was used with a mouse.
The development of Windows 1.0 was lead by Bill Gates. Although it received a lot of critisism at the time, it was an important step in the development of the future versions of Windows.
The Windows 1.0 interface in itself doesn't have many interface icons and it's desktop view doesn't attempt to be as realistic as that of the early Macintosh and Xerox systems, but applications such as Paint made use of icon-based interfaces. Windows 1.0 did not allow overlapping windows, instead all windows were tiled. This apparently was a conscious design choice that was made to differentiate it OS from Macintosh.
You can find a browser based Windows 1.0 emulator here: www.pcjs.org/devices/pc/machine/5160/cga/256kb/win101/
- McInnes, K. (2011) Rockstar Icon Designer, Rockable Press.