Mohan, try this. Call this method in the Button Click event. public static void CloseAllForms() { //Create a Collection to Store all Opened Forms. List<Form> formsList = new List<Form>(); //All all opened forms into a Collection. foreach (Form frm in Application.OpenForms) { //Execulde the Current Form. if (frm.Name == "Form1") continue; else formsList.Add(frm); } //Now Close the forms foreach (Form frm in formsList) { frm.Close(); } }