Windows XP in a Nutshell

Organization of the Registry

The Registry is enormous and complex; a full Registry might easily contain 15,000 keys and 35,000 values. Entire books have been written about it, and we can’t do it justice here. Our purpose in this section is to arm you with a basic understanding of how the Registry is organized, not to document individual values in detail or suggest changes you might want to make with Registry Editor.

Tip

David A. Karp’s book Windows Me Annoyances provides many tips and tricks that rely on the Registry. If you can still find Ron Petrusha’s out-of-print book, Inside the Windows 95 Registry , you’ll find lots of useful information there. While aimed primarily at software developers and covering Windows 95, it contains several chapters aimed at experienced users. In particular, see Chapter 1 to Chapter 3, which give a good overview of the Registry and a detailed description of how to use Registry Editor. Also see Chapter 8.

The top level of the Registry is organized into five main root branches. By convention, the built-in top-level keys are always shown in all caps, even though the keys in the Registry are not case-sensitive. (For example, HKEY_CURRENT_USER\SOFTWARE\MICROSOFT\Windows is identical to HKEY_CURRENT_USER\Software\Microsoft\Windows.) Their purposes and contents are listed in the following summaries. Note that the root keys are sometimes abbreviated for convenience in documentation (although never in practice); these abbreviations are shown in parentheses. ...