Posts Tagged ‘registry’

What is the Windows Registry?

registry-cleaner If you are not well versed with the inner workings of a computer, you probably have no idea of what a registry is or what purpose it serves. The registry is a database integrated into most Windows operating system. Serving as a repository of sorts, the registry is designed to store information regarding system files and configurations, user preferences, hardware devices and instructions installed programs need to function properly.

 When you open an application, such as Microsoft Word, the Windows operating system queries the registry to find out where the launch instructions for that particular program are stored. When new hardware or software is installed, a user downloads a file from the internet or simply changes their desktop screen, this is where that information is stored. In fact, a large majority of the activities that occur on your computer are noted in this area.

The Importance of the Windows Registry

The registry is an essential element of the Windows operating system. This sensitive area is so vital to your computer that without its presence, your machine would not be able to function at all. Upon startup, a Windows-based computer reads configuration data in the registry. This allows the system to determine which settings must be applied, what drivers needed to be loaded, and what system resources must be allocated for the machine to work.

Because this data is stored on your local hard drive, the information is made available to Windows each time the computer is booted up. The registry is not only essential for the normal operation of your computer, but also in providing you with a way to customize the Windows environment to suit your particular preference and needs.

Architecture of the Windows Registry

registry-cleaner The Windows registry is structured in hierarchical fashion. This architecture consists of main keys, keys and values. Below we have provided details on each component:

Main Keys – Also referred to as hives, the main keys are positioned at the top of the hierarchical structure with each key holding information for a certain category. For instance, one main key might contain details regarding software applications installed on the computer. The main keys found in the registry all depend on the version of Windows installed on your computer.

Here is more information about the possible main keys in your Windows registry:

HKCU (HKEY_CURRENT_USER_ – Contains preferences and configuration data for the user currently logged on to the system. When another user is simultaneously logged on to the same computer, the information this main key contains changes according to that particular user.

HKLM (HKEY_LOCAL_MACHINE) – Contains configuration data for the actual machine. The information stored in this main key remains the same no matter what user is logged on to the system.

HKCR (HKEY_CLASSES_ROOT) – Contains data that is relevant to the main user interface. Examples of this type of information would be shortcuts and file associations.

HKU (HKEY_USERS) – Contains data for each and every user that has ever logged onto the computer.

HKCC (HKEY_CURRENT_CONFIG) – Contains data concerning configurations for hardware devices currently installed on the machine. This particular main key is directly linked to the HKLM hive listed above.

HKDD (HKEY_DYN_DATA) – Contains data regarding plug-and-play hardware. This particular main key is only found in registries on Windows 95, 98 or ME platforms. In these environments, it is also linked to the HKLM hive.

Keys and Subkeys – In relation to the Windows operating system, a key represents an organizational unit found in the registry. They act as containers and may either store values, or lower-level keys known as subkeys. Subkeys are quite similar to typical folders as they may contain other folders or values while resting in the registry.

Values – Often referred to as entries, values are like files to a folder as they contain the data that is actually being stored in either a key or subkey. The registry stores a number of different value types but the most common are strings, DWORD and binary values.

The best way to visualize the registry is to view it like the folder/file tree structure on your Windows computer. The main keys, keys and subkeys essentially represent the path that must be traveled in order to access the actual data that is stored in the file, which in this case, is the value.

Though we don’t all need to be computer technicians, having a basic understanding of how the registry works is important. This centralized area is critical to the functioning of your PC and one day, you just might need to access it.