Dos has long been the Achilles heel of the PC and has limited its development. It has also been its strength in that it provides a common platform for all packages. DOS and Windows 3.x operated in a 16-bit mode and had limited memory accessing. Windows 3.0 provided a great leap in PC systems as it provided an excellent graphical user interface to DOS. It suf­fered from the fact that it still used DOS as the core operating system. Windows 95/98 and Windows NT have finally moved away from DOS and operate as full 32-bit protected-mode operating systems. Their main features are:
  • Run both 16-bit and 32-bit application programs.

  • Allow access to a large virtual memory (up to 4 GB).

  • Support for pre-emptive multitasking and multithreading of Windows-based and MS­DOS-based applications.

  • Support for multiple file systems, including 32-bit installable file systems such as VFAT, CDFS (CD-ROM) and network redirectors. These allow better performance, use of long file names, and are an open architecture to support future growth.

  • Support for 32-bit device drivers which give improved performance and intelligent mem­ory usage.

  • A 32-bit kernel which includes memory management, process scheduling and process management.

  • Enhanced robustness and cleanup when an application ends or crashes.

  • Enhanced dynamic environment configuration.


File System Device Driver User Account Virtual Memory Parity Block 


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Copyright information

© Springer Science+Business Media Dordrecht 1999

Authors and Affiliations

  • Bill Buchanan
    • 1
  1. 1.Napier UniversityScotland

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