If you don't want anyone to tamper with your custom ESET Nod 32 antivirus settings, you can set a password that will definitely limit the manipulation allowed. Still your antivirus shall be fully functional.
Here's how to proceed:
Open your Antivirus
Click the Setup tab > Enter entire advanced setup tree
Scroll to the "User interface" section > "Access setup" section
In the right pane:
Check the box next to "Password protect settings"
Click on the "Set password button"
A small dialog shall open, simply fill in your password and confirm it.
Validate with the OK button.
You shall have the confirmation that your settings are henceforth password protected.