Chapter 3. The Registry

Every time you change a setting in Control Panel, add hardware to your system, install an application, or even rearrange icons on your desktop, Windows stores the corresponding data in your Registry. The Registry is a database containing all the settings for Windows XP, as well as the applications installed on your system. Knowing how to use the Registry effectively is important for improving performance in Windows, troubleshooting all kinds of problems, and, most importantly, customizing Windows XP beyond what is possible with the dialog boxes scattered throughout the interface.

All of your file types (also known as associations; see Section 4.3) are stored in the Registry, as well as all of the network, hardware, and software settings for Windows XP, and all of the particular configuration options for most of the software you've installed. The particular settings and data stored by each of your applications and by the various Windows components vary substantially, but you can use some special techniques to figure out undocumented settings and uncover hidden functionality, regardless of how the data is stored. What's especially helpful is that most of the settings stored in the Registry are named in plain English rather than with obscure codes and acronyms. You shouldn't take this fact for granted, but it does help quite a bit in finding settings and troubleshooting problems.

Word to the wise: you can irreversibly disable certain components of Windows XP or even prevent Windows from running by changing certain settings in the Registry. Now, the vast majority of settings in the Registry are mostly harmless, but nonetheless, I strongly recommend taking the steps outlined in this chapter to prevent making irreversible changes, such as taking advantage of Registry patches to backup portions of the Registry before you edit a single value. Furthermore, backing up your entire system will ensure that none of your valuable data or programs are compromised and will undoubtedly save you hours of hassle in the event of a stupid mistake. Believe me, I've been there.