HOW TO PROTECT MY WEB APPLICATIONS FOLDER

Good day my code masters,

Hope this mail meet you all in good health, i have some bit of challenge i wrote a web application where some file are in Admin folder while others are in Personnel Folder and on the root folder i have the login file and web.config file.

I don't want anonymous visitor to just access the page, all i want is for all visitors to pass through the Login form if you have the user role you may only access the personnel folder only the user with admin role can access anywhere in the folder.

Please guide me on how to do these without using the visual studio ASP.NET Administrator Tools, I want to use C# code to achieve this.

i need your help.