1. Start your computer and then press the 'F8' key while it is starting up. This will take you to the 'Advanced Boot Options' menu. Scroll down to the 'Safe Mode' option with the arrow keys on your keyboard.
2. Press the 'Enter' key and wait for the computer to boot into Safe Mode. This should take about 45 seconds to complete. Click the 'Start' button when the computer has booted and then click the 'Run' box.

3. Type 'Regedit' into the run box and press the 'Enter' button. This will start your registry checker tool. Wait for the registry checker tool to complete the scan. This should take about one to five minutes to complete. When the scan has completed, you will be prompted to restart your system.
4. Click the 'Restart' button when prompted to restart your computer. The computer will restart as normal and the Code 19 error will be fixed.