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Microsoft Windows is a range of closed source proprietary commercial operating environments for personal computers and also servers. The range was first introduced by Microsoft in 1985 and eventually has come to dominate the world personal computer market. All recent versions of Windows are fully-fledged operating systems.

Windows was developed for IBM PC compatible computers (these were based on Intel x86 architecture), and to this day, almost all versions of Windows are made for this hardware-platform (although some versions of Windows NT were made for other architectures ). The popularity of Windows made Intel CPUs more popular and vice versa. In fact, the term Wintel became used to describe PC compatible computers running a version of Windows.

Versions

The term Windows is used as a collective term for several generations of products, which can be classified into the following categories:

• 16-bit Operating environments. Although they are often thought of as just graphical user interfaces or desktops, mostly because they use MS-DOS for filesystem services, 16-bit Windows versions already have their own executable file format and provide their own device drivers (graphics, printer, mouse, keyboard and sound). Most importantly, from the beginning they allow the user to (non-preemptively) multi-task graphical applications, something which competitors like GEM do not offer. Finally, they implement an elaborated segment-based software virtual memory scheme, which allows to run applications larger than available memory: code segments and resources are swapped in and thrown away when useless or memory becomes scarce and data segments move in memory when a given application has relinquished processor control. Examples include Windows 1.0 (1985) and Windows 2.0 (1987) and its close relative Windows/286.

• Hybrid 16/32-bit operating environments. Windows/386 introduced a 32-bit protected mode kernel and virtual machine monitor. For the duration of a Windows session, it provided a device virtualization for the disk controller, video card, keyboard, mouse, timer and interrupt controller. The user-visible consequence was that it became possible to preemptively multitask multiple MS-DOS environments in separate windows (graphical applications required switching the window to full screen mode). Windows applications were still multi-tasked cooperatively inside one of such real-mode environments. Windows 3.0 (1990) and Windows 3.1 (1992) perfected the design, notably thanks to virtual memory and loadable virtual device drivers (VxDs) which allowed them to share arbitrary devices between multitasked DOS windows. Most important, Windows applications could now run in 16-bit protected mode (when Windows was running in Standard or 386 Enhanced Mode), which gave them access to several megabytes of memory and removed the obligation to participate in the software virtual memory scheme. They still ran inside the same address space, where the segmented memory provided a degree of protection, and multi-tasked cooperatively. For Windows 3.0 Microsoft also rewrote critical operations from C into assembly, making this release faster and less memory-hungry than its predecessors.

• Hybrid 16/32-bit operating system. With the introduction of 32-Bit File Access in Windows for Workgroups 3.11, Windows could finally stop relying on DOS for file management. Leveraging this, Windows 95 introduced Long File Names, reducing the 8.3 DOS to the role of a boot loader. MS-DOS was now bundled with Windows; this notably made it (partially) aware of long file names when its utilities were run from within Windows, but angered the competition. The most important novelty was however the possibility of running 32-bit multi-threaded preemptively multitasked graphical programs. There were three releases of Windows 95 (the first in 1995, then subsequent bug-fix versions in 1996 and 1997, only released to OEMs, which added extra features such as FAT32 support). Microsoft's next OS was Windows 98; there were two versions of this (the first in 1998 and the second, named "Windows 98 Second Edition", in 1999). This was an evolutionary enhancement, in much the same relation to Windows 95 as Windows 3.1 had been to 3.0. In 2000, Microsoft released Windows Me, which used the same core as Windows 98 but adopted the visual appearance of Windows 2000, as well as a new feature called system restore, allowing the user to set the computer's settings back to an earlier date. Compared to previous upgrades, comparatively few people bothered to switch to ME: by this time most power users had already jumped over to the NT family. This can be defended by the fact that Microsoft left little time for Windows Millennium to become popular before announcing their next version of Windows.

• 32-bit operating systems originally designed and marketed for higher-reliability business use with no DOS heritage. The first release was Windows NT 3.1 (1993, numbered "3.1" to match the Windows version and to 1-up OS/2 2.1, its main competitor at the time), which was followed by NT 3.5 (1994), NT 3.51 (1995), and NT 4.0 (1996); the latter of which introduced the Windows 95 interface. Microsoft then moved to combine their consumer and business operating systems. Their first attempt, Windows 2000, failed to meet their goals, and was released as a business system. The home consumer edition of Windows 2000, codenamed "Windows Neptune", ceased development and Microsoft released Windows ME in its place. Eventually "Neptune" was merged into their new project, Whistler, which later became Windows XP. XP finally rendered DOS obsolete, and since then a new business system, Windows Server 2003, has expanded the top end of the range, and the forthcoming Windows Longhorn will complete it. Windows CE, Microsoft's offering in the mobile and embedded markets, is also a true 32-bit operating system.

• 64-bit operating systems, the newest category, are designed for AMD's AMD64 CPU architecture, and Intel's Intel Architecture 64-bit, and EM64T. The 64-bit Windows family comprises Windows XP Itanium edition and x64 Edition and Windows Server 2003; Windows XP Professional and server x64 editions have reached RTM status in March 30, 2005. Itanium editions already came out in 2002. Early indications are that Windows Longhorn, the projected successor to Windows XP, will be released in both 32-Bit and 64-Bit versions.

Interface

The most obvious feature of the more recent Windows versions (since Windows 95 and NT 4.0) is the desktop, which is similar to the "Workplace Shell" introduced by IBM for OS/2 2.0 in 1992, an object-oriented GUI running on the OS/2 Presentation Manager. The Windows desktop has produced a significant change in the way people and computers interact; it is possible to perform many common tasks with very little computer knowledge, including some quite complex ones.

Windows XP introduced a new visual style dubbed "Luna", which updated the classic Windows style (a plain grey box look) with a more graphical appearance. The new style features bold colors and a larger titlebar and start button, leading many to call it the "playskool" interface (after a popular brand of children's toys) [1] (http://www.winntmag.com/ActiveDirectory/Article/ArticleID/23597/ActiveDirectory_23597.html) [2] (http://www.kingcountyjournal.com/sited/story/html/71914) [3] (http://labmice.techtarget.com/FAQ/winxpfaq.htm) and others to call it the "Teletubbies" interface (after the children TV show Teletubbies, also partly because of Windows XP's default wallpaper, a grassy plain with a blue sky, which resembles the set of the TV show) [4] (http://www.theregister.com/2002/01/25/get_the_teletubbies_windows_xperience/). Users can still elect to use the old Windows 95/2000 visual style.

There is a view that modern operating systems need to cater for the vastly increased user base with a lower average computer skill level and the increased power and complexity of modern computer systems. Therefore, some technically savvy users accuse the Windows interface of isolating the user from too much of the inner workings of the computer, making it more difficult to control and configure some system features, although many such features can be now controlled also from the command-line or by scripting. However, this has always been an issue to some extent with GUI operating systems, and, to a lesser extent, almost all operating systems, by definition.

Popularity

Thought to be installed on over 90% of personal computers, Windows has achieved enormous market penetration due in large part to the domination of MS-DOS in the early days of PC compatible computers (IBM-PC clones), and also because it is the primary platform for Microsoft Office and its proprietary document formats (which, however, are also supported by a large number of non-Microsoft products including the open-source OpenOffice.org office suite as well) used by most microcomputer users, as well as the fact that Microsoft is one of the few companies that license their OS to hardware manufacturers (for example, Apple does not license Mac OS X to anyone, nor does Sun license Solaris to anyone). Due to Microsoft's exclusive licensing agreements with many computer vendors, Windows comes pre-installed on most computers (as a bundled OEM version), making it the default choice for much of the market. Most consumers do not delete Windows and install another operating system. For some consumers, Windows is the only valid option as their computing environment is mandated by their workplace; for others, the wide variety of applications that is available for the platform limits their desire to switch to other operating systems. While many users have made an informed choice to run Windows, a large number are entirely unaware that there are other choices.

Security

Security has been a major issue with Windows family products for many years. Most modern operating systems were designed for security in a multi-user and/or networked environment and have a relatively small number of security issues. Windows was originally designed for ease-of-use on a single-user PC without a network connection, and did not have security features built in from the outset. Combined with occasionally flawed code (such as buffer overruns) Windows has been the successful target of worms and virus writers numerous times. The Blaster worm of August 2003 is a recent example.

It is unclear whether the security problems with the Windows line are particularly systemic for Microsoft, or are so prevalent merely because Windows dominates the world's desktops, thus leading attackers to concentrate on Windows systems before any other type. Nevertheless, Microsoft publicly admitted their ongoing security problems shortly after the turn of the century and (according to their press statements) now claims to regard security as their number one priority.

Microsoft releases security patches through its Windows Update service approximately once a month, although critical updates are made available at shorter intervals. In Windows 2000 and Windows XP, updates can be automatically downloaded and installed if the user elects to do so.

Many security experts are advising Windows users to take steps to increase the security of their systems. A study conducted by Kevin Mitnick and marketing communications firm, Avantgarde, found that an unpatched Windows XP system only lasted 4 minutes on the Internet before it was compromised. [5] (http://www.avantgarde.com/ttln113004.html) The AOL/National Cyber Security Alliance Online Safety Study of October 2004 determined that 80% of Windows users were infected by at least one spyware/adware product. [6] (http://www.staysafeonline.info/news/safety_study_v04.pdf) Much documentation is available describing how to increase the security of Microsoft Windows products. Typical suggestions include deploying Microsoft Windows behind a hardware firewall, running anti-virus and anti-spyware software, and installing patches as they become available through Windows Update. Some suggest replacing specific programs which are often targeted by crackers with alternatives, such as replacing the web browser Internet Explorer with Mozilla Firefox, and replacing the email client Microsoft Outlook with Mozilla Thunderbird.

In 2001, Microsoft started talking about a controversial security initiative called Palladium. The system has since been renamed "Next Generation Secure Computing Base". Palladium is a system intended to allow a program to verify that it is unmodified, and is running on "trusted" hardware with "trusted" drivers and a "trusted" architecture. This, in theory, assures the software that it is running on unmodified software and hardware. Palladium has a particular use in DRM systems. A side effect will be to lock out "untrusted" operating systems at the hardware level: this is likely to impact Linux in particular, since there is no single canonical Linux which can be certified, and many users consider the ability to customise the system one of its main attractions. Some conspiracy theorists hold that this is the secret reason behind the system, although in practice it is unlikely that Microsoft will try to prevent Linux vendors such as Red Hat from having their products certified. As of 2004, Palladium has not resulted in any commercial products.

Initiatives

Microsoft has a number of new initiatives planned or in progress: .NET, Next-Generation Secure Computing Base, and the "Longhorn" operating system, which is due in 2006 according to some Microsoft executives. Further down the road, there is the "Blackcomb" operating system, which is due some time around 2010, and will have both client and server versions.

Current versions

• Windows Mobile for embedded systems (formerly known as Windows CE)
  • Pocket PC for PDAs
  • Pocket PC Phone Edition for hybrid PDA/mobile phones
  • Smartphone for mobile phones
  • Portable Media Center for Digital Media Players
• Windows XP for desktops and notebooks
  • Windows XP Starter Edition, for new computer users in developing countries
  • Windows XP Home Edition, for home desktops and notebooks
  • Windows XP Home Edition N, as above, but without a default installation of Windows Media Player, as mandated by an EU ruling
  • Windows XP Professional Edition, for business and power users
  • Windows XP Professional Edition N, as above, but without a default installation of Windows Media Player, as mandated by an EU ruling
  • Windows XP Tablet PC Edition, for notebooks with touch screens
  • Windows XP Media Center Edition for desktops and notebooks with an emphasis on audio, video, and PVR capability
• Windows Server 2003 for servers
  • Small Business Server for first server installations (up to 2 processors)
  • Web Edition for basic web serving (up to 2 processors)
  • Standard Edition for smaller server applications that don't require clustering(up to 4 processors)
  • Enterprise Edition for larger server applications, and clustering(up to 8 processors)
  • Datacenter Edition for mainframe like servers (up to 128 processors)
  • Storage Server for Network Attached Storage Devices
• Windows XP Embedded for embedded systems

Past versions

• DOS-Based
  • 1985 November - Windows 1.0
  • 1987 December 9 - Windows 2.0
  • 1990 May 22 - Windows 3.0
  • 1992 August - Windows 3.1
  • 1992 October - Windows for Workgroups 3.1
  • 1993 November - Windows for Workgroups 3.11
  • 1995 August 24 - Windows 95 (Version number: 4.00.950)
  • 1998 June 25 - Windows 98 (Version number: 4.1.1998)
  • 1999 May 5 - Windows 98 Second Edition (Version number: 4.1.2222)
  • 2000 June 19 - Windows Me (Version number; 4.9.3000)
• NT Kernel-Based
  • 1993 August - Windows NT 3.1
  • 1994 September - Windows NT 3.5
  • 1995 June - Windows NT 3.51
  • 1996 July 29 - Windows NT 4.0 - the last version which ran on RISC architectures like DEC Alpha, MIPS and PowerPC. Later versions concentrated on x86-based hardware and - mainly as server OSs - the IA-64 line of CPUs.
  • 2000 February 17 - Windows 2000 (Version number: NT 5.0.2195)

Cancelled versions

• 1996 May 3 - Windows Nashville (windows 96) (cancelled)
• 1997-1998 - Cairo (a "true object-oriented OS") planned after Windows NT; if released would be similar to DesktopX (but at a lower level)
• 1999 December - Windows Neptune was sent out to betatesters but was never released. Should have been successor to Windows 2000.

Future versions

• 2006 - Windows codename "Longhorn" is scheduled to be released.
• 2010 - 2012 - Windows codename "Blackcomb".

Emulation and virtual machine software

Emulation or the use of "virtual machines" allow the use of some Windows applications without using Microsoft Windows.

• WINE - an incomplete open source implementation of the Windows API, allowing one to run some Windows applications on x86 Unix-based platforms, including Linux.
• Cedega (formerly known as WineX) is TransGaming Technologies' proprietary fork of WINE, which is designed specifically for running games written for Microsoft Windows under Linux
• Java programming language by Sun Microsystems - Java is an object-oriented programming language developed initially by James Gosling and colleagues at Sun Microsystems. (see also JVM - the Java Virtual Machine)
• Microsoft .NET Web Application Platform (Compare alternatives: The Mono and Rotor Projects)
• ReactOS - Open Source operating system, aimed to be compatible with Windows NT apps and drivers, although still very much in its infancy at the moment.
• Freedows and Alliance OS - A very ambitious project, and a subsequent spinoff, that tried to clone Windows but withered away.
• Project David - Ambitious and controversial project to fully emulate Windows programs to run on other OSs.
• Codeweavers CrossOver Office product, also to fully emulate Windows programs to run on other OSs.
• VMWare PC Emulator software
• Microsoft Virtual PC (formerly by Connectix)
• Captive NTFS - A software "wrapper" for fuller, more-compatible open-source implementations of the Windows NTFS file system
• QEMU - Free software written by Fabrice Bellard that implements a fast processor emulator, allowing a user to run one operating system within another
• DOSBox - An emulator which creates a DOS-like environment primarily intended for running older, MS-DOS-based PC computer games which may not run properly on newer PCs.
• ScummVM - A virtual machine which allows one to play LucasArts Adventure Games games which use the SCUMM system on platforms other than those where versions were originally released.

See also

• Blue Screen of Death
• Microsoft Anti-Virus for Windows
• Windows Media
• Windows Explorer
• Microsoft Visual Studio
• Volume Shadow Copy Service
• Hardware
  • Hardware abstraction layer
  • Hardware description language
  • Windows Driver Model
  • Device driver
  • WinHEC
  • VGASAVE
• List of operating systems
• Comparison of operating systems
• Sticky keys
• Windows Longhorn - Next Generation Windows Platform
• Windows Blackcomb - Next Generation Server Platform

External links

• Microsoft's Official Windows Website (http://www.microsoft.com/windows/)
• GUIdebook: Windows Gallery (http://www.aci.com.pl/mwichary/guidebook/interfaces/windows) - A website dedicated to preserving and showcasing Graphical User Interfaces
• Microsoft's Officially Supported "Windows Pre-installation Environment" (http://www.microsoft.com/licensing/programs/sa/support/winpe.mspx) (aka WinPE) - for making boot-able "Live" Administrative Windows CD's
• Bart Lagerweij's "Bart PE" (http://www.nu2.nu/pebuilder/) - a powerful free 3rd-party "PE" alternative (not endorsed nor supported by Microsoft)
• Captive NTFS (http://www.jankratochvil.net/project/captive/) - An open-source effort to create a "wrapper" around the original Windows NTFS file-system DLL's in order to more fully implement compatibility between file read/write operations for Unix-like operating systems
• ReactOS (http://www.ReactOS.com/) Project to make a compatible Open Source version of Windows
• Windows-Help-Desk.com (http://www.windows-help-desk.com/) Free Windows Help Tutorials
• Computing.net (http://www.computing.net/) Free user support-group community forums
• "Time to Live on the Network" (http://www.avantgarde.com/xxxxttln.pdf) a Security Study by Kevin Mitnick and AvantGarde
• AOL/National Cyber Security Alliance Online Safety Study (October 2004) (http://www.staysafeonline.info/news/safety_study_v04.pdf)
• Securing Microsoft Windows (for Home and Small Business Users) (http://www.dwheeler.com/essays/securing-windows.html)
• Windows tips (http://www.dehumanizer.com/wiki/index.php/Windows_tips) (security, stability, etc.)
• Download.com (http://www.download.com/) - Application Programs for download, for Windows Operating Systems
• NT Security (http://www.NTSecurity.com/) - Excellent Security information about Windows NT (2000/XP/2003 Server/Longhorn)
• Symantec Anti-Virus Research Center (http://www.SARC.com/) - Excellent informational security resource, and Symantec are makers of Norton Anti-Virus (3rd party software sold separately)
• Network Associates' McAfee (http://www.McAfee.com/) - makers of McAfee Anti-Virus (3rd party software sold separately)
• GriSoft (http://www.GriSoft.com/) makers of AVG Anti-Virus (free version available)
• Avast (http://www.Avast.com/) makers of Avast Anti-Virus (free version also available)
• ClamAV (http://www.ClamAV.net/) - Clam Anti-Virus for PC's, workstations, and gateways (free and open-source)
• Sophos.com (http://www.Sophos.com/) An excellent security information resource, and makers of Sophos Anti-Virus for PC's, workstations, and gateways
• Microsoft Anti-Spyware product site (http://www.microsoft.com/athome/security/spyware/software/default.mspx) (formerly known as the "Giant.com" Anti-Spyware application) - anti-spyware/adware/malware/trash-ware cleaner-upper
• www.Safer-Networking.org (www.Kolla.de) (http://www.Safer-Networking.org/) - Official website of the "SpyBot Search and Destroy" program - anti-spyware/adware/malware/trash-ware cleaner-upper
• LavaSoft USA Ad-Aware (http://www.LavaSoftUSA.com/) - anti-spyware/adware/malware/trash-ware cleaner-upper
• JavaCool Software Spy Blaster (http://www.JavaCoolSoftware.com/) - anti-spyware/adware/malware/trash-ware cleaner-upper
• WebRoot's Spy Sweeper program (http://www.WebRoot.com/) - anti-spyware/adware/malware/trash-ware cleaner-upper
• Windows (http://www.bredel.homepage.t-online.de/Windows/Windows-English/windows-english.html) Tips and tricks for Windows 98, ME, NT, 2000 and XP