The first Windows OS started to be developed in September 1981 and it was sold in stores on November 1985 under the name Windows 1.0.
Bill Gates wanted to call Windows 1.0 "Interface Manager" but Rowland Hanson (marketing expert) persuaded him that Windows was a better name. Microsoft sent out a press kit featuring a squeegee and washcloth to announce the launch of Windows 1.0. The press kit was sent out in November 1983, a full two years before the operating system was eventually released.
After taking a look at a very early pre-release version of Windows in 1983, Byte Magazine declared it a system that would "offer remarkable openness, reconfigurability, and transportability as well as modest hardware requirements and pricing." The system requirements for Windows 1.0 were 256KB of RAM, DOS 2.0 and two floppy drives. The retail price for Windows 1.0 was $100. Adjusted for inflation, that's equivalent to $177 in today's dollars  roughly the same price you'd pay today for a full retail edition of Windows XP Home.
Windows 1.0 was out for only about two weeks before Microsoft released version 1.01, in order to fix several bugs. This was the beginning of a long tradition of service packs and other incremental fixes that continues to this day.
From the beginning, Windows could display color, if hooked up to a color monitor with an appropriate graphics adapter, while Macs available at the time were strictly black and white affairs. This led PC Magazine to declare that "after an hour In-a-vision (the first of the native applications to be offered for Windows), even the most devoted Macintosh user will be a convert."
Windows 1.0 used a primitive file manager called MS-DOS Executive. A later version of this program, which is largely unchanged from the original, is available for download, and still runs under Windows XP !
Despite the limitations of the bundled apps, early ads for Windows boasted that the system included "an extremely useful set of applications."
