Python code to close all open application in windows

you can use the psutil library to close all open/active windows applications and then open a single exe using the subprocess module:

import psutil
import subprocess

# Kill all open/active processes
for proc in psutil.process_iter():
    proc.kill()

# Open a single exe using subprocess
subprocess.Popen("C:\path\to\exe.exe")

Note that the psutil.process_iter() returns a list of all running processes on the system, and proc.kill() method is used to kill each process. The subprocess.Popen method is used to open the exe file. Make sure that you provide the correct path to the exe file. Please be aware that this script will close all open applications, including any unsaved work in progress.
You should use it with caution, or for testing purpose only.

you can instead reduce all open windows. this is safer!

import win32gui
import win32con
import subprocess

def minimize_all():
    def callback(hwnd, hwnds):
        if win32gui.IsWindowVisible(hwnd) and win32gui.IsWindowEnabled(hwnd):
            hwnds.append(hwnd)
        return True

    hwnds = []
    win32gui.EnumWindows(callback, hwnds)
    for h in hwnds:
        win32gui.ShowWindow(h, win32con.SW_MINIMIZE)

minimize_all()
# Open a single exe using subprocess
subprocess.Popen("C:\path\to\exe.exe")

This script uses the win32gui library to enumerate all open windows, and the win32con library to minimize them.