4.6. WINDOWS NT Architecture

The Windows NT operating system has a modular architecture.

The first module — user mode — allows the user to interact with the system. This level includes environment subsystems and a security subsystem. A set of instrumental subsystems that support different types of user programs is called an environment subsystem. Such subsystems include \ Ut-32, which supports 16- and 32-bit Windows applications and DOS applications, the subsystem that controls the user interface of Windows NT, and others. The security subsystem provides the user with a legitimate login to the system.

The second module - the kernel mode - ensures the safe execution of user applications. At this level there are three integrated modules: performing services, core, level of hardware abstractions.

The interaction between the subsystem core and the environment subsystems is performed by the executing services consisting of the system service and the kernel mode service. The system service is the interface between the subsystems of the application environment and the kernel mode services. The kernel mode service consists of the following program modules:

• I / O manager, allowing you to control the process of input-output information;

• Object Manager, which manages system operations that are performed on objects (use, rename, delete, protect an object);

• Security Control Manager to ensure system security;

• tools for calling local procedures that support the work of user applications and subsystems of the environment and ensure the exchange of information;

• A virtual memory manager, which is a service that manages physical and virtual memory;

• Process Manager, which regulates the actions of processes (creation, deletion, logging); distributing address space and other resources between processes.

All system processes are controlled by the Wndows NT kernel, which is also responsible for optimal system performance.

The part of the system that ensures the independence of the upper levels of the OS from the specifics and differences of specific hardware is called the level of hardware abstractions. This module contains all the hardware-dependent information.

The graphical user interface is designed to create comfortable conditions for the user when working with Windows NT. This interface is intuitive, simple, convenient when launching programs, opening and saving files, working with files, disks and network servers. The multi-window GUI in Windows NT is based on an object-oriented approach. The work of the user in this approach is directed mainly at the documents, and not at the program. Any document is loaded by opening the file that contains this document, and the program that creates the file being opened is automatically loaded.

The user interface of Windows NT contains the following elements: "Desktop"; "Task bar"; "Start menu"; "Context menu"; "Windows NT application menu system"; labels: “My Computer”, “Network Neighborhood”, “Trash”, “Internet Explorer”, “Inbox”, “Portfolio”; "Window"; Fonts; "Help system Windows NT". The desktop includes shortcuts depicting programs, documents and devices. Shortcuts allow you to quickly access programs, folders, documents, computer devices or network.