In Windows, what is the registry?

On this page:

• Introduction
• Registry files
• Editing the registry

Introduction

The Windows registry is the database used by Windows 2000, XP, and 2003 to keep track of the settings for the operating system and all installed programs.

Registry files

Windows NT, 2000, XP, and 2003 store most registry information in files called "hives". Hives are stored permanently on the hard drive and are not necessarily the same from one computer to another. Only administrators can access hives or delegate the rights to access them. Hives for the "Machine" keys are found in the system32 directory, within the Windows directory, which is on the drive where Windows is installed. For example, if your computer has Windows 2000 installed on drive C:, then you'll find hives in these directories:

Note: If Windows was installed on drive D:, then the path would be  D:\windows\system32\Config  or  D:\WINNT\System32\Config.

Hives for the "User" keys are found in the Documents and Settings folder, also on the drive where Windows was installed. The various User hives are scattered throughout different subfolders in the Documents and Settings folder (some in LocalService, some in the actual user folder, etc.).

For a definitive list of where your Windows 2000 or later computer stores its registry hives, open the Registry Editor and navigate to:

You will see a list of keys indicating the location of each specific hive. For example, for the Machine Security entries, you'll see something like:

For this example, that refers to  C:\Windows\system32\config\SECURITY  (or  D:\Windows...  etc., if Windows is installed on the D:\ drive).

All hive file locations for your computer will be listed there.

Editing the registry

You can edit the registry from a command prompt by entering regedit (in all Windows versions) or regedt32 (Windows 2000 only). The regedt32 program is the more powerful (in Windows XP and later, regedit is equivalent to regedt32), as it can also search the registry on other computers on the network.

Warning: Edit the registry at your own risk. If you make an error while editing the registry, you can potentially cause Windows to fail or be unable to boot, requiring you to reinstall Windows. Always back up the registry before making any changes. For information on how to back up your registry, see In Windows NT, 2000, and XP, how do I back up the registry? If you feel uncomfortable editing the registry, seek the help of a computing support provider.

Also see:

• In Windows NT or 2000, how do I turn off the login screen on my personal workstation?
• In Windows Me or XP, how can I restore my computer to a previous configuration?
• In Windows Me or XP, how can I save my computer's configuration for use in a System Restore?
• In Windows NT, 2000, and XP, how do I back up the registry?