Operating system Chromium OS. Microsoft Windows is a family of proprietary operating systems designed by Microsoft Corporation and primarily targeted to Intel architecture based computers, with an estimated 88.9 percent total usage share on Web connected computers. The latest version is Windows 10. In 2011, Windows 7 overtook Windows XP as most common version in use. Microsoft Windows was first released in 1985, as an operating environment running on top of MS-DOS, which was the standard operating system shipped on most Intel architecture personal computers at the time. In 1995, Windows 95 was released which only used MS-DOS as a bootstrap. For
Windows NT startup process The installer can also be run from a MS-DOS command prompt so previous versions of Microsoft Windows that are already installed can be upgraded. To run the installer from a MS-DOS based operating system such as Windows 98 or Windows ME, the user must start the system "in DOS mode" and then execute I386/WINNT.EXE on the CD-ROM. A floppy disk containing MS-DOS can be used to start the installer. Versions of the installer in floppies were also available for sale. From Windows Vista onwards, the installer runs from BOOT.WIM which contains a bootable version of Windows PE. Windows PE 2.0