how 2 fully save unity projects before complete format of computer?

Hi I have to reinstall windows so i want to save some unity projects I really want to do this right so to avoid mistakes,
How do I save the entire projects and can i save them on a thumb drive etc.

I want to save entire projects scripts scenes etc, all of it/them
please explain in detail thanks

Just copy and paste your project folder onto any other storage device. This project folder contains your whole project. This is all you need to do in order to take a backup of your project. The project folder is the folder in which you have created your Unity project i.e. the folder you create while creating a new project.