Close all open forms except the main menu in C#

Question

Trying to close all forms except for the main menu using

FormCollection formsList = Application.OpenForms;

with a foreach loop and saying,

Answer 1

I know this is old but I needed to perform this same scenario and came up with a elegant and simple way to achieve this as follows

        Form[] formsList = Application.OpenForms.Cast
().Where(x => x.Name == "Form1").ToArray();
        foreach (Form openForm in formsList)
        {                
            openForm.Close();
        }

This will close ALL windows that where opened called Form1