Anyone ever heard of Windows 1.0? Well this was the first version of Microsoft Windows ever! It was released in November 1985 and believe it or not, never took off. In the linked video, I think you'll see why. Windows really didn't take off until around 1992 when Windows 3.1 came out.
I actually once believed that the first Windows was Windows 3.1. A visit to a Windows timeline on Microsoft's website back in 2005 told me otherwise.