You're free do disagree. DOS was an OS at the time and command.com was its command shell. It abstracted access to some devices like printer, serial ports and disks. If provided file system. It had nothing to do with graphics cards, sound cards etc. CMD.EXE does the same thing, provides the DOS environment and a small part of hardware emulation (0xA000-0xFFFF mapping). So, DOS applications using this work perfectly, not knowing they're in windows application. Some applications (mostly games) needed hardware access to graphics and/or sound card, or other. For these you need an application like dosbox to emulate direct hardware access, which works great, runs almost any game without problems even on 64bit system.