High Quality Content by WIKIPEDIA articles! COMMAND.COM is the filename of the default operating system shell for DOS operating systems and the default command line interpreter on Windows 95, Windows 98 and Windows Me. It has an additional role as the first program run after boot, hence being responsible for setting up the system by running the AUTOEXEC.BAT configuration file, and being the ancestor of all processes. COMMAND.COM`s successor on OS/2 and Windows NT-based operating systems is cmd.exe. COMMAND.COM is also available on 32-bit versions of those systems to provide compatibility when running DOS applications within the NT Virtual DOS machine.