Microsoft Windows Operating System Essentials

Microsoft Windows, sometimes known as Windows, is a collection of proprietary graphical operating system families created and sold by Microsoft. Microsoft Windows is a trademark of Microsoft Corporation.

Microsoft Windows Operating System

Each of the families serves a specific segment of the computing industry. Windows NT and Windows IoT are currently active Microsoft Windows families; these may contain subfamilies (e.g., Windows Server or Windows Embedded Compact) but are not required to be active (Windows CE). Windows 9x, Windows Mobile and Windows Phone are just a few of the Microsoft Windows family that are no longer in use.

As a reaction to rising interest in graphical user interfaces, Microsoft released an operating system dubbed Windows on November 20, 1985, as a graphical operating system shell for the MS-DOS operating system (GUIs).

Microsoft Windows eventually surpassed Apple’s Mac OS, which had been released in 1984, to become the world’s most popular personal computer (PC) operating system, with more than 90 percent of the market.

Apple saw Windows as an unfair infringement on their invention in graphical user interface development, deployed on devices such as the Lisa and Macintosh. Windows is still the most widely used operating system on personal computers in all nations.

However, in 2014, Microsoft acknowledged that it had lost the majority of the total operating system market to Android due to the enormous increase in the number of Android devices being sold worldwide. The number of Windows devices sold in 2014 was less than a quarter of the number of Android devices sold in the same year.

On the other hand, this comparison may not be entirely applicable because the two operating systems are usually designed for distinct platforms. Nonetheless, figures for Windows server usage (equivalent to those of rivals) indicate a one-third market share, close to the figure for end-user use.

In October 2021, the most recent version of Windows for computers and tablets is Windows 11 (version 21H2), the latest version available. The most current version of Windows 10 for embedded devices is version 21H1 (Windows 10).

The most current version of Windows for server PCs is Windows Server 2022, version 21H2, which is available now. The Xbox One and Xbox Series X/S video game consoles run a customized version of Windows, available for purchase separately.

Learn about Microsoft Windows Version History

The word “Windows” refers to any or all of numerous versions of Microsoft operating system products that have been released over time. These are typically divided into the following categories:

Early versions of Windows

Windows 1.0, released in 1985

Windows began in 1981 when Microsoft started working on a software named “Interface Manager.” Windows 1.0 was announced in November 1983 (after the Apple Lisa but before the Macintosh), but it wasn’t launched until November 1985.

Windows 1.0 was intended to compete with Apple’s OS but ultimately flopped. Windows 1.0 is an add-on to MS-DOS. The MS-DOS Executive is the Windows 1.0 shell. There was also a Calculator and a Calendar.

Windows 1.0 prohibits window overlapping. Instead, they’re tiled. The only exception is modal dialog boxes. Many windows examples were supplied as part of the Windows Development Library sold with the C development environment.

Windows 2.0, introduced in December 1987, outperformed its predecessor. It improves the user interface and memory management. Microsoft modified Windows 2.03 from tiled to overlapping windows.

As a result of this modification, Apple Computer sued Microsoft for copyright infringement. Windows 2.0 also included more advanced keyboard shortcuts and could consume more RAM.

Windows 2.1 came in two flavors: Windows/286 and Windows/386. With the paged memory model, Windows/386 may mimic expanded memory utilizing available extended memory and the virtual 8086 modes of the Intel 80386.

Despite its moniker, Windows/286 operates on both Intel 8086 and 80286 CPUs. It works in real mode but can access high memory.

The runtime-only versions came with early Windows software from third parties and allowed them to execute their Windows applications on MS-DOS without the complete Windows feature set.

Early Windows versions were commonly referred to as graphical shells, owing to their usage of MS-DOS for file system functions.

However, early Windows versions included many conventional operating system capabilities, including their executable file format and device drivers (timer, graphics, printer, mouse, keyboard, and sound).

Unlike MS-DOS, Windows enabled users to run many graphical apps simultaneously. A complex software virtual memory mechanism allows Windows to execute applications more prominent than available memory.

Code and resource segments are swapped in/out as memory becomes limited; data segments are relocated in memory when an application relinquishes processor control.

Windows 3. x

Windows 3.0 (1990)

Windows 3.0, launched in 1990, enhanced the architecture by allowing multitasking DOS applications to share arbitrary devices. Windows 3.0 applications can operate in protected mode, gaining access to many megabytes of memory without using the software virtual memory method.

They share the same address space, protected by segmented memory. Windows 3.0 improved the user interface. Microsoft rewrote C code into assembly. Windows 3.0 is the first Microsoft Windows version to sell 2 million copies in six months.

Windows 3.1, released on March 1, 1992, has a new look. Windows for Workgroups 3.11, a particular version with integrated peer-to-peer networking functionality, was launched in August 1993. It came with Windows 3.1. Windows 3.1 support was terminated on December 31, 2001.

Windows 3.2, launched in 1994, is a Chinese-language upgrade to Windows 3.1. The upgrade only affected this language version, as it addressed problems with the Chinese writing system.

Manufacturers supplied Windows 3.2 with a ten-disk MS-DOS version that included Simplified Chinese characters in basic output and some translated tools.

Windows 9x

Windows 95 was launched on August 24, 1995. Windows 95, while still MS-DOS-based, offered native 32-bit programs, plug-and-play hardware, preemptive multitasking, extended file names of up to 255 characters, and improved reliability.

The Start menu, taskbar, and Windows Explorer shell were introduced in Windows 95, replacing the preceding Program Manager. When Windows 95 was eventually retired in 2001, it was the most widely used operating system globally.

It was released in four OEM Service Releases (OSR), each comparable to a service pack. The initial OSR of Windows 95 included Microsoft’s web browser, Internet Explorer. Windows 95 mainstream support ended on December 31, 2000, while extended support concluded on December 31, 2001.

On June 25, 1998, Microsoft released Windows 98, which included the Windows Driver Model, support for USB composite devices, ACPI, hibernation, and multi-monitor support.

Windows 98 introduced Active Desktop interaction with Internet Explorer 4 and other Windows Desktop Update features (a series of enhancements to the Explorer shell, also made available for Windows 95).

Microsoft launched Windows 98 Second Edition in May 1999. It also included Internet Explorer 5.0 and Windows Media Player 6.2. Windows 98 mainstream support ended on June 30, 2002, and extended support concluded on July 11, 2006.

Microsoft introduced Windows Me (Millennium Edition) on September 14, 2000. Windows Me had faster boot times than previous versions, expanded multimedia functionality, and improved security.

But Windows Me was criticized for its speed, instability, hardware compatibility, and real mode DOS support loss. PC World ranked Windows Me as the 4th worst tech product ever introduced by Microsoft.

Windows NT

In November 1988, a new Microsoft development team began work on “NT OS/2”, a reworked version of IBM and Microsoft’s OS/2. With preemptive multitasking, various processor architecture support, and POSIX compatibility, NT OS/2 was designed to be a safe multi-user operating system.

In fact, after the success of Windows 3.0, the NT development team opted to redesign the project to utilize Win32, an expanded 32-bit version of the Windows API. Win32 had a similar structure to the Windows APIs but also supported the NT kernel’s capabilities.

Following Microsoft’s acceptance, work on Windows NT, the first 32-bit version of Windows resumed. But IBM resisted and eventually developed OS/2 on its own.

Windows NT was the first Windows OS with a mixed kernel. The hybrid kernel was built as a modified microkernel, influenced by Richard Rashid’s Mach microkernel at Carnegie Mellon University, but not satisfying all microkernel criteria.

Windows NT 3.1 (named after Windows 3.1) was introduced in July 1993, including desktop workstations and servers versions.

Windows NT 3.5 was launched in September 1994 and was followed by Windows NT 3.51 in May 1995, which provided more enhancements and support for the PowerPC platform.

Windows NT 4.0, introduced in June 1996, brought the Windows 95 interface to the NT series. Microsoft introduced Windows 2000 on February 17, 2000. The Windows NT moniker was abandoned to focus on the Windows brand.

Windows XP

Windows XP was introduced on October 25, 2001. Windows XP sought to merge the consumer-oriented Windows 9x series with the NT architecture, a move Microsoft stated would improve performance over its DOS-based predecessors.

With Windows XP, Microsoft would also deliver a revamped user interface that included an updated Start menu and a “task-oriented” Windows Explorer, simplified multimedia and networking features, Internet Explorer 6, and support for Microsoft’s. NET Passport services.

Windows XP was sold in two editions: “Home” for consumers and “Professional” for businesses and power users, with enhanced security and networking features.

Later, the “Media Center” version was made for home theater PCs, and the “Tablet PC” edition built for tablets was released. Windows XP mainstream support ended April 14, 2009. Extending support terminated on 4/8/14

Microsoft altered its server release timetable after Windows 2000; Windows Server 2003 was launched in April 2003. Windows Server 2003 R2 came out in December 2005.

Windows Vista

Windows Vista was launched for bulk licensing on November 30, 2006, and for consumers on January 30, 2007. New features included a revamped shell and user interface and significant technological modifications focused on security.

It came in several editions and was criticized for its performance, boot time, new UAC, and license agreement. Windows Server 2008 was launched in early 2008.

Windows 7

Windows 7 and Windows Server 2008 R2 RTM (release to manufacturing) was launched on July 22, 2009, with the general release three months later on October 22, 2009.

Unlike its predecessor, Windows Vista, which included a considerable number of new capabilities, Windows 7 was designed to be compatible with existing programs and hardware.

Windows 7 has multi-touch support, a revamped taskbar with revealable jump lists containing shortcuts to commonly used files and actions within programs, a home networking system called HomeGroup, and speed enhancements.

Windows 8 and 8.1

Windows 8 was generally available on October 26, 2012. Windows 8 introduced a new user interface based on Microsoft’s Metro design language, optimized for touch-based devices like tablets and all-in-one PCs.

The Start screen now employs big tiles for touch interactions and displays continuously updated information, including a new class of programs developed specifically for touch-based devices.

For netbooks with 800600-pixel displays, the new Windows version needed a minimum resolution of 1024768 pixels.

Other improvements include:

  • Tighter interaction with cloud services and other online platforms.
  • A new Windows RT version for devices with ARM architecture.
  • A new keyboard shortcut for snapshots.

Windows 8.1 was launched on October 17, 2013, offering improved live tile sizes, deeper OneDrive integration, and other changes. Windows 8 and Windows 8.1 have been criticized for removing the Start menu.

Windows 10

Microsoft released Windows 10 on September 30, 2014. It was published on July 29, 2015, and resolves issues encountered with Windows 8. The Start Menu is back on PC, as is a virtual desktop system and the option to run Windows Store programs in desktop windows rather than full-screen.

Get Windows 10 (for Windows 7 and 8.1) or Windows Upgrade is claimed to be available to update eligible Windows 7 with SP1 and Windows Phone 8.1 devices ( Windows 7 ).

Microsoft announced the switch from Perforce to Git in February 2017. It involved 3.5 million files in a 300 GB repository. Its technical staff used Git in around 8500 contributions and 1760 Windows builds every day by May 2017.

Microsoft revised its lifespan policy pages for Windows 10 in June 2021, soon before announcing Windows 11. Support for Windows 10 will end on October 14, 2025.

Windows 11

Windows 11 was revealed as the successor to Windows 10 on June 24, 2021. The new OS was meant to be more user-friendly. It came out on October 5, 2021. Windows 10 users will be able to upgrade for free.

Windows 365

Windows 365 subscriptions for virtualized Windows PCs will be available starting July 2021, Microsoft revealed. It is a web service that offers Windows 10 and Windows 11 developed on top of Azure Virtual Desktop.

The new service will be cross-platform, allowing both Apple and Android customers to access the operating system. The subscription-based service will work on any computer with a web browser.

Microsoft’s new service aims to capitalize on the rising trend of organizations adopting a hybrid work environment, where employees split their time between the office and home.

Because the service is web-based, Microsoft may avoid publishing it on Google Play or the Apple App Store.

For corporate and enterprise clients, Microsoft announced the availability on August 2, 2021.

Multilingual Support

Windows 3.0 has multilingual support. The Region and Language Control Panel allows you to alter the keyboard and interface language.

Components for all supported input languages, such as Input Method Editors, are installed automatically by Windows. Third-party IMEs can be installed if the provided one is not suitable.

The operating system’s interface languages are free to download. However, some are restricted to particular Windows versions.

Windows Surface Laptop

Language Interface Packs (LIPs) are redistributable and may be installed for any edition of Windows (XP or later) – they translate much of the Windows interface but not all of it and require a base language.

Most languages in emerging markets utilize this. Full Language Packs are only available for specific Windows versions. They don’t need a foundation language and are often used for languages like French or Chinese.

These languages are not accessible through the Download Center but through Windows Update (except Windows 8).

Changes in the Windows interface language do not affect installed programs. Application developers determine language availability.

Language packs of any sort may be downloaded from a central place in Windows 8 and Windows Server 2012. The PC Settings program in Windows 8.1 and Windows Server 2012 R2 has a similar page.

However, entire language packs may be loaded for any version except Single Language, targeting emerging markets.

Platform Support

Before the x86-based personal computer became the leading professional platform, Windows NT supported several systems. MS-DOS supported PowerPC, DEC Alpha, and MIPS R4000.

However, the operating system regarded several of these systems as 32-bit. Save for the third generation x86 (known as IA-32 ) or newer in 32-bit mode. Windows 2000 eliminated support for all platforms except these.

The Windows NT client line still uses IA-32, while the Windows Server line stopped supporting it with Windows Server 2008 R2.

Microsoft updated Windows to accommodate Intel’s Itanium architecture (IA-64). Windows XP and Windows Server 2003 Itanium versions were released alongside their x86 equivalents.

Until 2005, Windows XP 64-Bit Edition was the final Windows client to support Itanium. Windows Server 2008 R2 is the last Windows operating system that supports Itanium architecture.

Microsoft launched Windows XP Professional x64 Edition and Windows Server 2003 x64 Edition on April 25, 2005. Windows Vista was the first NT client to be released in both IA-32 and x64 versions. It still supports x64.

While ARM is still utilized for Windows smartphones with Windows 10, tablets running Windows RT will not be upgraded. Windows 10 Fall Creators Update (version 1709) and later adds compatibility for ARM-based PCs.

Windows 11 is the first to abandon 32-bit hardware.

Windows CE

Windows Embedded Compact 7 media player UI idea.

Windows CE (Windows Embedded Compact) is a version of Windows designed for small computers such as satellite navigation devices and mobile phones.

WinCE is a specialized kernel for Windows Embedded Compact. Microsoft sells Windows CE licenses to OEMs. Windows CE offers the technological basis for OEMs and device makers to develop their user interfaces and experiences.

Windows Mobile Operating System

The Dreamcast uses both Windows CE and Sega’s proprietary OS. Windows Mobile was built on top of Windows CE. Windows Phone 7 used both Windows CE 6.0 R3 and Windows CE 7.0 components. But Windows Phone 8 operates the same NT kernel as Windows 8.

Microsoft Windows Embedded Compact is not confused with the NT kernel-based Windows Embedded Compact or Windows Embedded XP.

Xbox OS

Xbox OS is an unofficial name for the Windows version seen on Xbox consoles. It is now possible to run three operating systems simultaneously on Xbox One, one for the core operating system, one for games, and one for apps.

Every month, Microsoft upgrades the Xbox One’s OS, which may be downloaded through Xbox Live and installed on the console or by utilizing offline recovery images obtained from a PC.

It was initially based on NT 6.2 (Windows 8) and now runs on NT 10.0. This system is also known as OneCore or Windows 10 on Xbox One. In addition to limited backward compatibility with previous generation hardware, the Xbox 360’s system is backward compatible with the original Xbox.


Windows was initially intended for ease of use on a single-user PC without a network connection and did not include security measures. Windows NT and its successors were designed for security, including network security and multi-user PCs, but not for Internet security, as Internet use was still rare in the early 1990s.

Because of these architectural flaws, programming problems (e.g., buffer overflows), and Windows’ ubiquity, worm and virus authors frequently attack it.

Microsoft distributes security fixes via Windows Update around once a month (typically the second Tuesday of the month), with essential updates released more often.

Updates can be downloaded and installed automatically in Windows 2000 SP3 and Windows XP if the user chooses. Consequently, consumers installed Service Pack 2 for Windows XP and Service Pack 1 for Windows Server 2003 faster than usual.

While Windows 9x allowed for numerous user profiles, they had no idea of access privileges and did not enable concurrent access, making them unsuitable for multi-user environments. They also only implemented limited memory protection. Their lack of security was severely criticized.

Windows NT, on the other hand, is a proper multi-user and protects memory. However, previous to Windows Vista, the initial user account created during setup was an administrator account, which was also the default for new users.

Although Windows XP had limited accounts, most home users didn’t utilize them, partly owing to the number of apps that required administrator access.

User Account Control (UAC) in Windows Vista alters this. Logging in as a regular user creates a logon session and assigns a token with minimal rights. Thus, the new login session cannot make system-wide modifications.

When signing in as an Administrator, two tokens are assigned. The first token has all administrator powers, while the second is confined to regular user capabilities.

This results in a lower privilege environment even under an Administrator account. An unrestricted token is used when a program asks for greater rights or “Run as administrator” is clicked.

File Permissions

‘Local groups’ are used to apply file permissions to files and folders, and these groups are made up of members of other ‘global groups.’ It varies depending on the Windows version. However, these global groups can contain other groups or individuals.

Other operating systems, such as Linux and NetWare, differ in that permissions are set statically to the file or folder, but this system does not.

The use of AGLP/AGDLP/AGUDLP allows for the imposition of a basic set of static permissions and the alteration of account groups without the need to reapply file permissions to the affected files.

Application Recovery and Restart

Application Recovery and Restart (ARR) is a feature that allows applications to store data and state information before they quit due to an unhandled exception or when the application stops responding. If the user requests it, the program will also be restarted.

When a software installer upgrades a component of the software, or when the computer has to restart as a result of an update, an application can also be restarted.

It should be noted that in order to allow automatic program restart when an installer updates an application, both the application and the installer must be written in the proper manner.

Error Handling

When programs are properly developed, they incorporate error-handling logic that allows them to recover gracefully from unforeseen failures. The program may need to request user involvement when an error occurs, or it may be able to recover on its own if the fault is not fatal. In severe situations, the program may lock the user out of the machine or even shut it down completely.

System Error Codes

System Error Codes are quite broad in scope, with each one having the potential to appear in any of many hundreds of different places across the system. The explanations of these codes, as a result, are not able to be extremely precise.

The use of these regulations necessitates a certain degree of study and analysis. These failures must be documented in both the programmatic and the runtime contexts in which they are encountered.

Because these codes are specified in WinError.h and are available to anybody to use, they are occasionally returned by software that is not part of the operating system.

And, on occasion, the code is returned by a function that is buried deep in the stack and disconnected from the code that is processing the issue.

Windows Error Reporting

Users can utilize the error reporting function to inform Microsoft of application faults, kernel faults, sluggish programs, and other application-specific problems.

With the use of the error reporting function, Microsoft may give customers troubleshooting information, remedies, and/or upgrades for the specific problems they are experiencing.

Developers can make use of this infrastructure in order to obtain information that can be utilized to enhance their apps.

The Windows user interface provides an option for users to activate error reporting. They have the option of reporting problems for certain programs alone.

Administrators have the ability to change these settings through the use of Group Policy.

Microsoft’s Windows Desktop Application Program allows developers to register with the program in order to get information about the difficulties that consumers are having with their apps and to assist customers in resolving these issues.

Using Application Recovery and Restart, developers can ensure that customers do not lose data when their program fails and that users can immediately resume their work when the application has been restarted.