File Explorer

Explorer is the application responsible for the main user interface of Microsoft Windows. Development of Explorer immediately began with the development of Windows 95. The Explorer interface was later ported to Windows NT. In Windows 8, the Start Menu, which is a component of Explorer, was deprecated in favor of the new Start Screen. Windows 10 will bring a Start Screen-esque Start Menu, an improved implementation of virtual desktops, and other new features.

Cabinet Windows 95
Explorer was first introduced in Windows 95, but it did not start out looking like its final design. In early builds, Explorer was named Cabinet, the Taskbar acted as a folder, and the Start Menu was not present; It was instead divided into three menus. The first menu (denoted by the Windows logo) acted as a system menu where you could access applications through the 'Run' dialog, manipulate windows and shutdown Windows. The second menu (denoted by a magnifying glass) acted like a place where you could search for files. The last menu was the 'Help' menu where you could get help and get basic system information.

Shell Technology Preview/NewShell
NewShell is a pack that adds the new NT4 (alpha) shell to NT 3.51.NewShell's UI is similar to that of NT4 1130. It causes the kernel to jump to 4.00. A final (RTM) version of NewShell was never released.