The following websites offer a wealth of information on the Windows Registry.
Microsoft Windows 2003 Server Resource Kit Registry Reference
The Registry Reference is a searchable technical reference that provides detailed
descriptions of selected Windows Server 2003 registry content. It describes the subtrees,
keys, subkeys, and entries that advanced users want to know about, including many entries
that cannot be changed by using Windows tools or programming interfaces. It also
contains essential background information about the Windows registry.
Microsoft Windows 2000 Server Resource Kit Registry Reference
This site provides detailed descriptions of Windows 2000 registry content, such as the subtrees,
keys, subkeys, and entries that advanced users want to know about, including many entries that
cannot be changed by using Windows 2000 tools or programming interfaces.
Microsoft Windows Knowledge Base
The Microsoft Windows Knowledge Base offers hundred of thousands of articles of which many
are related to the Windows Registry
JSI FAQ - Windows NT/2000/XP/2003 Server Tips and tricks
JSI Inc. offers some excellent resources including a searchable database containing thousands of registry hacks.