heart and soul of Microsoft Windows Operating System

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1. INTRODUCTION
The registry is the heart and soul of Microsoft Windows Operating System. The registry contains the configuration data that makes the operating system work. The registry is everything-it is the brain of the operating system. The registry enables developers to organize configuration data in ways that are impossible with other mechanisms, such as INI files. More importantly, it enables you to customize Windows Operating System in ways you can’t through the user interface. Windows Operating System and every application that runs on Microsoft’s latest desktop operating system do absolutely nothing without consulting the registry first. When you double-click a file, Windows consults the registry to figure out what to do with it. When you install a device, Windows assigns resources to the device based on information in the registry and then stores the device’s configuration in the registry.


. REGISTRY BASICS
The registry has a subtle but important role in Microsoft Windows Operating System. On one hand, the registry is passive—it’s just a big collection of settings sitting on your hard disk. On the other h and, it plays a key role in all those activities. The settings in the registry determine how Windows appears and how it behaves. They even control applications running on your computer. This gives the registry great potential as a tool for power users or IT professionals, enabling them to customize settings that aren‘t available in the user interface. Windows stores configuration data in the registry. The registry is a hierarchical database, which you can describe as a central repository for configuration or a configuration database. A hierarchical database has characteristics that make it ideally suited to storing configuration data.


The Past
MS-DOS got its configuration data from Config.sys and Autoexec.bat. The primary purpose of Config.sys was to load device drivers, and the primary purpose of Autoexec.bat was to prepare MS-DOS for use by running programs, setting environment variables, and so on. Every application that ran on MS-DOS was responsible for man aging its own settings. Microsoft Windows 3.0 alleviated the limitations of Autoexec.bat and Config.sys a bit by providing INI files for storing settings. While the performance with these files left something to be desired, they formed the basis for today’s registry.



Values

Each key contains one or more values. In my analogy with Windows Explorer, values are similar to files. A value’s name is similar to a file’s name. A value’s type is similar to a file’s extension; which indicates its type. A value’s data is similar to the file’s actual contents. Click a key in Registry Editor’s key pane, and the program shows the key’s values in the value pane. In the value pane, you see three columns, which correspond to the three p arts of a value: