Windows is a graphical operating system developed, sold and marketed by Microsoft. It was first introduced in November 1985.
Windows has undergone many evolutions since its initial release. Today, it is one of the world’s most popular OSes.
It has large developer support, so there are plenty of games and applications to choose from. It also supports plug and play hardware, making it easy to connect new devices.
System Architecture
The system architecture of windows system includes the kernel, hardware abstraction layer (HAL), and user-mode components such as the Windows API and graphical device interface (GDI). The HAL hides differences in physical hardware and allows applications to interact with the operating system in a uniform way.
The memory manager implements a virtual memory system, controlling the paging of memory in and out of physical storage to disk storage. It also manages a session space, allowing multiple processes to share the same kernel-mode pages.
User applications don’t call native Windows operating system services directly; instead, they call one or more subsystem dynamic-link libraries (DLLs). The role of these DLLs is to translate a documented function into an internal and generally undocumented system service call. Then the DLL sends the request to a process running in the environment subsystem server that serves the application.
Hardware Abstraction Layer
The Windows operating system supports a wide variety of hardware and software devices, making it easier for users to install and run various applications and programs. It also enables users to connect to networks and share data.
The hardware abstraction layer (HAL) is a component of the Windows operating system that provides a standardized interface for application software to access the computer’s underlying hardware. It hides the low-level details of hardware and allows device drivers to communicate with it in a more general manner.
The HAL is installed on your Windows computer in the form of a set of routines. These routines are stored as dl_ and ex_ files on the installation CD and can be accessed with the DOS command expand. The dl_ and ex_ files are compressed and renamed to hide their contents.
Subsystem
Windows Subsystem for Linux (WSL) allows developers to run a GNU/Linux environment — including most command-line tools, utilities and applications — directly on Windows computers without the overhead of a dual boot setup or virtual machine. Users can install WSL through the Microsoft store and choose from a variety of supported Linux distributions.
The architecture of WSL includes a user-mode session manager service, minimized Pico processes that handle Linux system calls and a kernel-mode driver to emulate the Linux kernel. This allows Linux commands to operate on Windows hardware and for Linux memory, file and screen I/O to be handled by the Windows kernel.
This feature also enables developers to use the same code in Windows and Linux environments. WSL uses a file system called VolFs that supports Linux conventions such as linking files, using names with characters not accepted by Windows and the directory structure.
Kernel-Mode Drivers
The kernel-mode drivers implement the low-level functionality that all other components of Windows depend upon. This includes things like hardware device interfacing, memory management and transactional logging.
User mode applications have restricted access to the underlying hardware and core operating system functions. They operate in a virtual address space that is private to them, so one application cannot modify data of another. This also ensures that if an application crashes, it doesn’t affect other applications or the operating system.
Kernel-mode drivers operate at a higher level of privilege, and are more likely to cause a blue screen of death than an ordinary user-level program. They must therefore be written to be incredibly stable, and to use techniques that differ from those of normal user-mode programming.
Applications
A software program that runs under the Windows operating system is called a Windows application. It provides a consistent user experience and takes advantage of Windows-specific features. It also offers broad compatibility with existing hardware and software infrastructure. Windows applications are essential in various domains, including software development and key industries such as healthcare and finance.
Facilitating Security: Windows apps allow users to protect their computers or laptops from virus and malware attacks. They also provide tools for file management and access configuration.
In addition to allowing users to manage their email and calendar, Windows applications can also connect them with other online services such as Google, Apple, and Microsoft. These applications can also be used offline. They run on a server, so the user does not need to update them regularly.