This page briefly explains what the Windows Registry is, why it's a good idea to back it up, and how to restore Registry backups created by CCleaner. For specific instructions about restoring Registry backups, go to Restoring Registry backups in 3 steps further below.
What is the Windows Registry?
The Windows Registry is a set of files that contains settings for your Windows PC, such as what program to use to open HTML files, when your antivirus program should run, or what desktop background you use.
Why is it helpful to back up the Registry?
Windows stores many important system changes in the Windows Registry. Creating a backup allows you to revert files and settings to a previous configuration if you encounter any problems after cleaning the Registry.
Restoring Registry backups in 3 steps:
1) Find where you saved the backup on your PC via Windows File Explorer.
2) Identify the Registry backup file. The name will be cc_date_time.reg by default.
3) Right-click the file, and choose Merge, as you can see in the screenshot below.
Note: Once you have done this, Windows attempts to restore the Registry backup.