The Windows Registry is a database that is used to store configuration settings for a range of purposes in one organised location. It is primarily designed to store settings for the operating system to use such as settings for device drivers, services, and the kernel, but other software can use it too.
Data in the Registry is stored with two basic parts: keys and values. Registry keys are case insensitive and are used as a label to identify the meaning of individual values or to provide further structure for subkeys. Values in the Registry can be used to store meaningful data such as version numbers, file paths, performance parameters, and other configuration options.
The Registry is structured so that there are overall system values which can be overridden by values tied to individual user accounts, this allows standard known-good configuration settings to be the default, while also allowing users to modify the settings for their own account without affecting other users.
At its core, the Registry is a database that stores its data in a binary format in one logical instance, although the data is actually spread across a number of different files on the disk. Using a binary database format rather than individual text-based configuration files provides a number of advantages, including the increased performance of reading binary data compared to text files and the standardised format and location of configuration data.
Another advantage of the Registry being in a database format is a data integrity feature called “atomic updates”, which means that if two processes attempt to modify the same value at the same time, one operation will complete before the other starts, each update is individual. Whereas with text files it is possible for this situation to become what’s known as a “race condition”, where both actions happen at the same time, leading to unpredictable results.
The registry can be accessed and edited through the default Windows program “regedit.exe” this can be found by using the Windows search function and typing “regedit”.
Tip: Great care should be taken when editing the Registry, as settings critical to Windows functionality are stored there. Editing the wrong Registry value can cause services to fail to launch, or even stop Windows from booting entirely.