How to Clean Windows XP registry

The operating system registry is where the operating system stores all of your computer's device and file associations, as well as critical information about drivers, directories, Windows applications and more. But as it grows in size, your OS performance may be compromised. Cleaning up the registry can help.

  • Click Start.
  • Click Run.
  • Type "regedit" into the text field and press Enter.
  • Here, you will see access to various entries in your Windows XP registry. They are organized by these primary sections: HKEY_CLASSES_ROOT, HKEY_CURRENT_USER, HKEY_LOCAL_MACHINE, HKEY_USERS and HKEY_CURRENT CONFIG. Each section contains a different set of entries related to different aspects of Windows XP operation.
  • Click the plus sign (+) next to one of the root directories to see a more detailed list. (This second level will have more directories to choose from, and will help you to find entries you need to clean the registry.)
  • Delete entries in the registry that are either causing conflicts or are no longer needed. Do this by pressing Delete, or by right-clicking on your mouse and choosing Delete entry.

You might consider purchasing a third-party registry application to help you clean your Windows XP registry — many include backup capabilities to retrace their steps in the event of a critical error.

Another option? You can clean your boot records by changing which programs load them at startup. Click through both the LOCAL_MACHINE and CURRENT_USER directories until you reach Software/Microsoft/Windows/Run and RunOnce. From here, you can clean out registry entries that are causing certain programs to run on startup.

A few additional tips:

  • Back up your system files before you clean your Windows XP registry. Choose System Restore from the System Tools, or you use the ntbackup.exe file that comes with Windows XP. Windows XP Home Edition users can download the backup application from the Microsoft Web site.
  • Do not clean the Windows XP registry unless you are absolutely sure you know which entries you are deleting and which entries must remain. If you delete vital registry entries, your PC performance will suffer. Always double-check the definition of entries before you modify them.