Windows is a series of graphical operating systems developed by Microsoft to overcome the limitations of MS-DOS. The first successful versions were Windows 3.0 in 1990, followed by Windows 98, 2000, XP, Vista, 7, and the latest Windows 8. Common features of Windows OS include program execution, interfaces, input/output handling, error handling, memory management, and process management. Current versions include Windows 2000, XP, Vista, 7, and 8, with each subsequent version introducing new features and improvements related to performance, security, and usability.