【How-to】Is dos window an operating system

Examples of Operating system are : UNIX (Solaris, IRIX, HPUnix, Linux, DEC Unix) Microsoft Disk Operating System (MS-DOS), WIN95/98, WIN NT, OS/2 etc. … There are various versions of DOS like MS-DOS(Microsoft), PC-DOS(IBM), Apple DOS, Dr-DOS etc. WINDOWS was similar to APPLE Mach operating system interface on IBM-PC.