The Windows Registry

• System Configuration Utility
  
  The graphic above is the opening screen of regedit.exe, the registry editor in Windows XP. It looks and functions similarly in all versions of Windows from 98 onward. Each of the five top-level items, HKEY_CLASSES_ROOT, HKEY_CURRENT_USER, HKEY_LOCAL_MACHINE, HKEY_USERS, and HKEY_CURRENT_CONFIG, contain many subtrees with subentries in binary or string form.
  
  To see the registry, go to Start, then Run, and type "regedit" to go to the Registry Editor directly, or type "msconfig" for the System Configuration Utility and choose "Tools," which is the last tab on the right. Registry Editor is among the listed options.
  
  It is perfectly safe to look at the registry. If you want to make changes to it, there are several things you should do first.
  
  

Before Cleaning the Registry

• Registered File Types
  
  Often registry problems prevent backups from being made, but if you can, back up all your important files now with your favorite backup program.
  
  Next, take precautions so that if an unwanted .reg file appears on your computer because of a malicious email attachment or website, its contents will not be automatically inserted into the registry. This can be done easily with the control panel. In category view, as opposed to classic view, go to Start/Control Panel/Appearance and Themes/Folder Options. Under "File Types," which is the third tab, scroll to the REG entry and click "Change." A window appears, asking which program will be the default for REG files. Choose "Notepad" from the list, and don't worry. You'll still be able to run Registry Editor.
  
  Next, in the program list, create a system restore point by going to Accessories/System Tools/System Restore. Give your restore point a descriptive name. The date will be added to the filename automatically. If anything goes wrong with the changes you make to the registry, you will be able to reset your system to a time before you made the changes.
  
  Now, back up the entire registry. Run the Registry Editor again. Make sure "My Computer" is highlighted. Now select "File" and "Export." Click "All" at the bottom of the screen and save the file as filetype .reg so it can be restored later if necessary. It's best to copy this file to a CD or flash drive.
  
  

Cleaning the Registry

• CCleaner - Registry Integrity screenshot
  
  Go to http://www.ccleaner.com and download the latest version of CCleaner. This excellent freeware program has been downloaded over 300 million times and has received many awards. CCleaner includes a fully featured registry cleaner. You can choose the parts of the registry you want to optimize.
  
  Look at your registry once or twice a year and clean out any unused or ambiguous entries. This will keep your computer running smoothly.