1. Download CCleaner from the Piriform website and save it to your Windows XP desktop. Double-click the 'CCleaner Installer' icon to run the installation wizard. Follow the prompts in the wizard until it completes and the CCleaner window opens.
2. Click the 'Registry' icon in the left-side pane of the CCleaner window. This sets the right-side pane to the Registry view.

3. Click the 'Scan for Issues' button at the bottom of the Registry view. This will open a progress bar, and CCleaner will begin listing Registry errors.
4. Save the list of errors to a text file when the scan is finished and the progress bar shows 100 percent. Place your cursor above the list of errors and right-click, and then click 'Save to text file' from the context menu. Choose a location for the text file and click the 'OK' button.
5. Click the 'Fix selected issues' button at the bottom of the Registry view pane. This opens a Registry backup prompt dialog box. Click 'Yes' to back up the Registry. Choose a location for the backup and click the 'OK' button. Once you have saved the backup to disk, the repair wizard will open automatically.
6. Click the 'Fix Issue' button in the wizard to repair each Registry error that CCleaner has identified. To skip a problem, click the '>>' button. To repair all of the problems automatically without an individual prompt for each error, click the 'Fix All Selected Issues' button. The repair wizard will close automatically when you have fixed or skipped each Registry error.