Microsoft Windows

Microsoft Windows is a family of Operating Systems developed by Microsoft. It currently uses the Windows Explorer shell.

The first versions of Windows were an operating environment for DOS. Later versions (9x) used DOS as a bootstrapper. Any version of Windows that uses the NT Kernel does not rely on MS-DOS.

Windows for DOS
During this time, Windows was a desktop environment for DOS, an OS inspired by CP/M. There is a dispute whether it can be considered an operating system. One side points on the fact that it did include it's own graphics drivers and program API, which OS's do aswell, however on the other side the argument is that it extensively used the MS-DOS API. Last version of this series is Windows for Workgroups 3.11.

Windows 9x
In 1995, Microsoft released Windows 95, which was based on the older Windows for DOS code, however it was a hybrid 16/32bit operating system, which made almost all existing Win32 applications able to run. Windows 95, because of its heritage, included MS-DOS, however many DOS apps were either entirely replaced with a Windows version (MS-DOS Shell could be considered one) or extended with Win32 code (Scandisk). Windows 9x, though, used MS-DOS essentially only as a bootstrapper. Windows ME was the last release of this series.

Windows NT
Windows NT (New Technology) is the current iteration of Windows. It is built on the NT microkernel (hence the name), which was originally intended for use in OS/2 3.0 but was rewritten after the Microsoft - IBM split. The first release based on the new kernel was Windows NT 3.1, the version number of which was designed so that eventual customers wouldn't consider it inferior to Windows 3.1, its DOS-based counterpart. With Windows XP, the NT series merged with Windows 9x, creating a single operating system for consumers and businesses. Windows Phone 8 is the first Windows Phone release based on the NT kernel. The most recent version of Windows based on the NT kernel is Windows 10.