Python Windows Automation: Change Wallpaper, Lock Screen, and Create Infinite Pop‑ups

This article provides a step‑by‑step guide for Windows automation using Python 3.7. It covers three projects: modifying the desktop wallpaper, locking the screen indefinitely, and generating endless pop‑up windows.

Tools and environment

Development environment: Python 3.7 on Windows 10

Libraries: win32api , win32con , win32gui , ctypes , os , random , time

Installation command: <code>pip install pywin32</code>

1. Change Desktop Wallpaper

The wallpaper settings are stored in the registry under HKEY_CURRENT_USER\Control Panel\Desktop . The script opens this key, sets the WallpaperStyle value, and calls win32gui.SystemParametersInfo to apply a new image.

<code>k = win32api.RegOpenKeyEx(win32con.HKEY_CURRENT_USER, 'Control PanelDesktop', 0, win32con.KEY_SET_VALUE)</code>

<code>win32gui.SystemParametersInfo(win32con.SPI_SETDESKWALLPAPER, img_path, win32con.SPIF_SENDWININICHANGE)</code>

Full source:

<code>import win32api   # Windows low‑level API
import win32con   # Constants for registry and system calls
import win32gui   # GUI functions
import os
import random
import time

def set_wallpaper():
    path = os.listdir(r'图片文件夹')
    for i in path:
        img_path = r'图片文件夹' + "\\" + i
        print(img_path)
        # Open registry key
        k = win32api.RegOpenKeyEx(win32con.HKEY_CURRENT_USER, 'Control PanelDesktop', 0, win32con.KEY_SET_VALUE)
        # 2 = stretch, 0 = center, 6 = fit, 10 = fill
        win32api.RegSetValueEx(k, "WallpaperStyle", 0, win32con.REG_SZ, '2')
        win32gui.SystemParametersInfo(win32con.SPI_SETDESKWALLPAPER, img_path, win32con.SPIF_SENDWININICHANGE)
        time.sleep(10)

set_wallpaper()</code>

2. Infinite Lock Screen

Using the ctypes library to call the Windows user32.dll function LockWorkStation inside an endless loop.

<code>def lock_windows():
    while True:
        user = windll.LoadLibrary("user32.dll")
        user.LockWorkStation()
lock_windows()</code>

3. Infinite Pop‑up Windows

The script repeatedly launches a new Command Prompt window via os.system('start cmd') . A warning is included for low‑performance machines and a command to close all opened cmd windows.

<code>for i in range(2000):
    os.system('start cmd')
# To close all cmd windows:
# start taskkill /f /im cmd.exe /t</code>

Packaging the scripts into a standalone executable can be done with pyinstaller -F your_script.py , allowing distribution to friends or colleagues.

Images in the original article illustrate registry paths and the visual effect of the wallpaper change.