Windows System Documentation

Introduction

The Windows operating system provides a robust and secure platform for both desktop and server environments. This documentation covers core system components, architecture, and APIs that enable developers to build powerful applications.

System Architecture

Windows is built on a hybrid kernel architecture combining microkernel elements with a traditional monolithic design. Key layers include:

Hardware Abstraction Layer (HAL) – abstracts hardware differences.
Kernel Mode – core services such as memory, process, and I/O management.
User Mode – includes subsystems like Win32, POSIX, and the .NET runtime.

                    // Sample code to query OS version
                    using System;
                    class Program {
                        static void Main() {
                            Console.WriteLine(Environment.OSVersion);
                        }
                    }
                

Process Management

Processes are the fundamental execution units in Windows. The OS provides APIs for creating, managing, and terminating processes.

                    // Create a new process
                    var startInfo = new System.Diagnostics.ProcessStartInfo("notepad.exe");
                    var process = System.Diagnostics.Process.Start(startInfo);
                

Memory Management

Windows employs a virtual memory manager that handles paging, allocation, and protection.

                    // Allocate unmanaged memory
                    IntPtr ptr = Marshal.AllocHGlobal(1024);
                    Marshal.FreeHGlobal(ptr);
                

Security

Security in Windows is based on a comprehensive model that includes user authentication, access control lists (ACLs), and security tokens.

Access tokens represent the security context of a process.
ACLs define permissions for objects like files and registry keys.