How to draw directly on the Windows desktop, C#?
Try the following: using System; using System.Drawing; using System.Drawing.Drawing2D; using System.Runtime.InteropServices; class Program { [DllImport(“User32.dll”)] static extern IntPtr GetDC(IntPtr hwnd); [DllImport(“User32.dll”)] static extern int ReleaseDC(IntPtr hwnd, IntPtr dc); static void Main(string[] args) { IntPtr desktop = GetDC(IntPtr.Zero); using (Graphics g = Graphics.FromHdc(desktop)) { g.FillRectangle(Brushes.Red, 0, 0, 100, 100); } ReleaseDC(IntPtr.Zero, desktop); } }