Backing Up the Windows Registry

The first thing you should do whenever you plan to modify the Registry is to make a complete backup of it. The operation of your computer depends on the Registry remaining intact. Deleting the wrong Registry key or changing a value to an invalid entry can cause your computer to become unusable Windows might not even start.

You can make a manual copy of the Registry, or rely on Windows to do the backups for you. Windows backs up the Registry every time you boot your computer. If you modify the Registry and your computer becomes unstable or will not boot, you can use the Recovery Console to restore a previous copy of the Registry. It's a good idea to learn how to use the Recovery Console before making any changes to your Registry.

NOTE

For more information on the Recovery Console, pick up a book on Windows XP such as Special Edition Using Windows XP Professional or Special Edition Using Windows XP Home.

Creating a Registry Backup: Windows 2000/XP

In Windows 2000 or Windows XP, use the following procedures to create a backup of the entire Registry:

1. Click Start, and then click All Programs in Windows XP or Programs in Windows 2000. Then click Accessories, System Tools, and Backup. This starts the Backup or Restore Wizard.

2. Click Advanced Mode.

3. Click the Backup tab.

4. Click the Job menu and select New.

5. Select the System State check box to back up your system settings, Registry, COM+ class registration database, boot files, and those files covered under Windows File Protection.

6. Select the appropriate backup destination from the list. For backing up to a file, type the path and filename you want to create.

7. Click Start Backup to display the Backup Job Information dialog box shown in Figure E.2.

   Figure E.2. The Backup Job Information box enables you to customize your backup job.

   

8. Click Advanced and select the Verify Data After Backup check box.

9. Select the backup type and click OK.

   NOTE

   You can also select the type of backup you want to perform. There are five different types of backup. A Normal backup backs up all the selected files and marks them as backed up. A Copy backup backs up all the selected files, but doesn't mark any as backed up. An Incremental backup backs up selected files only if they have been created or changed since the previous backup. All backed-up files are marked as backed up. A Differential backup backs up new or changed files but does not mark them as backed up. The last backup type, Daily, backs up only files that were created or modified today. When backing up the system state, you'll want to choose a Normal backup.

10. Click Start Backup to begin the backup job.

11. Click Close when the backup has completed.

You can also simply export the Registry key you're planning to change. To export a single Registry key, use the following steps:

1. Click Start, Run, type regedit, and click OK.

2. Locate the key that contains the value you plan to edit.

3. Select that key in the left pane of the Registry Editor.

4. Click File, Export to display Figure E.3.

   Figure E.3. Select a location to save your exported key.

   

5. Select a location for the file and type a filename.

6. Click Save. Your file will be saved with the extension .reg.

NOTE

Do not use the previous steps to export an entire hive (HKEY_CURRENT_USER). If you need to export an entire hive, use the procedures previously defined to back up the entire Registry.

Restoring a Corrupted Registry

If Windows won't boot, you can use the System Recovery Console in Windows XP or boot from an emergency repair disk in Windows 2000. Then simply follow the onscreen steps given to restore the last known good copy of your Registry.

If your computer boots but the Registry key you modified is simply not functioning properly, you can import the previously exported backup copy of the Registry key.

Open the Registry Editor by clicking Start, Run and typing regedit. Click OK to launch the Registry Editor. Select File, Import and select the .reg file that contains the information you previously backed up. Windows will notify you when it has successfully imported the information into the Registry.