Microsoft’s OS version are highly popular in desktop users. Microsoft adds various functinality in each newer version of os.
* Dos:- Microsoft DOS (Disk Operating System) is a command line user interface. MS-DOS was not designed to be a multi-user or multitasking operating system, but many attempts were made to add these capabilities. Terminate and Stay Resident (TSR) system calls were originally designed for device drivers and extensible plugins that enhanced or added features.
* Windows 95:- Windows 95 is a consumer-oriented graphical user interface-based operating system. Windows 95 supports 32-bit applications, which means that applications written specifically for this operating system should run much faster.
* Windows 98:- Windows 98 is GUI operating system successor to win 95. Win 98 support FAT32 file system, allowing it to support disk partitions larger than the two gigabyte maximum accepted by Windows 95.
* Windows NT:- First fully 32-bit version of Windows. Win NT support NTFS file system. NT was written in C, a high level language. There are actually two versions of Windows NT: Windows NT Server, designed to act as a server in networks, and Windows NT Workstation for stand-alone or client workstations.
* Windows 2000:- Windows 2000 was made available in four editions: Professional, Server, Advanced Server, and Datacenter Server. The Encrypting File System (EFS) introduced strong file-level encryption to Windows. It allows any folder or drive on an NTFS volume to be encrypted transparently to the end user. Windows 2000 introduced quotas, file-system-level encryption, sparse files and reparse points. Windows 2000 does not allow direct hardware access. All hardware access must be through the hardware abstraction layer (HAL).
* Windows Xp:- Windows XP is designed more for users who may not be familiar with all of Windows features and has several new abilities to make the Windows experience more easy for those users. Xp has a a completely new look and ability to change the look. New feature that automatically obtains updates from the Internet. Includes internet explorer 6 and new IM. Added support for different languages.
* Windows Server 2003:- There are number of improvements from 2000 server especially in Active directory, Group policy, Scripting and command line tools. Support for hardware based watchdog timer. Windows 2003 gives best result for .net studio.
* Windows Vista:- Vista is latest window os by microsoft. Vista includes updated graphical user interface and visual style dubbed Windows Aero, improved searching features, new multimedia creation tools such as Windows DVD Maker, and completely redesigned networking, audio, print, and display sub-systems, also increase the level of communication on networking.