Instructions
Power on the DSi without any games inserted in the DS or Game Boy Advance slots. The DSi's system settings menu will automatically load.
Select "Settings." A new menu will appear.
Scroll to the right to locate "Parental Controls." Tap it to open the "Parental Controls" menu.
Tap "Yes."
Enter your DSi's PIN, which you created when initially setting up parental controls, and tap "OK" to continue. The "Parental Controls" settings menu opens.
Tap "Clear Controls."
Tap "Yes" to finish turning off the DSi's parental controls.