If you protect your Bitdefender settings with a password (under Settings → General), anyone trying to change the Bitdefender settings will first have to provide that password. Be sure to remember your password or keep a record of it in a safe place.
If you forget the password, you will have to either reinstall Bitdefender or follow the steps below in order to reset it:
1. Download (save) on your PC the password reset tool from here.
2. Restart Windows in Safe Mode. To do that please follow the steps from this article.
3. In Safe Mode, right-click on the tool downloaded at step 1 and select Run as Administrator. A command prompt window will open. Wait until the Finished message appears.
4. Press any key to complete the process.
5. Restart the PC normally, and you will be able to make changes in the Bitdefender interface without being prompted for a password.