how to close all folders in windows?

Question

i have a visual studio form that opens specific folders by pressing buttons. it would be very convinitent if i had a button to close all folders. cant find how to do that.

i have a code to close a specific process but i dont know how to refrence a specific folder and even if i did i dont know to make it work for all folders.

i have:

 

Process[] _proceses = null;

_proceses = Process.GetProcessesByName("E:/1");

foreach (Process proces in _proceses)

{

proces.Kill();

}