Enumerate all windows on the desktop. To produce correct geometries, app.manifest must be added.

app.manifest

<?xml version="1.0" encoding="utf-8"?>
<assembly manifestVersion="1.0" xmlns="urn:schemas-microsoft-com:asm.v1">
  <assemblyIdentity version="1.0.0.0" name="MyApplication.app"/>
  <trustInfo xmlns="urn:schemas-microsoft-com:asm.v2">
    <security>
      <requestedPrivileges xmlns="urn:schemas-microsoft-com:asm.v3">
        <requestedExecutionLevel level="asInvoker" uiAccess="false" />
      </requestedPrivileges>
    </security>
  </trustInfo>

  <compatibility xmlns="urn:schemas-microsoft-com:compatibility.v1">
    <application>
      <!-- Windows 10 -->
      <supportedOS Id="{8e0f7a12-bfb3-4fe8-b9a5-48fd50a15a9a}" />
    </application>
  </compatibility>

  <application xmlns="urn:schemas-microsoft-com:asm.v3">
    <windowsSettings>
      <dpiAwareness xmlns="http://schemas.microsoft.com/SMI/2016/WindowsSettings">PerMonitorV2, PerMonitor</dpiAwareness>
    </windowsSettings>
  </application>

</assembly>

Program.cs

using System.Runtime.InteropServices;
using System.Text;

internal class Program
{
    static void Main(string[] args)
    {
        Console.WriteLine("Generation, Name, X,Y,Width,Height");

        foreach (var w in GetAllWindows())
        {
            Console.WriteLine(@$"{new string(' ', w.generation)}{w.generation}, {w.name}, {w.rect.left},{w.rect.top},{w.rect.Width},{w.rect.Height}");
        }
    }

    static IReadOnlyList<(int generation, string name, RECT rect)> GetAllWindows()
    {
        var list = new List<(int generation, string name, RECT rect)>();

        EnumWindows(
            Proc,
            0);

        return list.AsReadOnly();

        bool Proc(nint windowHandle, nint lParam)
        {
            var buffer = new StringBuilder(256);

            if (GetClassName(
                windowHandle,
                buffer,
                buffer.Capacity) > 0)
            {
                int currentGeneration = (int)lParam;
                int nextGeneration = currentGeneration + 1;
                var name = buffer.ToString();

                GetWindowRect(
                    windowHandle,
                    out RECT rect);

                list.Add((currentGeneration, name, rect));

                EnumChildWindows(
                    windowHandle,
                    Proc,
                    new IntPtr(nextGeneration));
            }
            return true;
        }
    }

    #region Win32

    [StructLayout(LayoutKind.Sequential)]
    struct RECT
    {
        public int left;
        public int top;
        public int right;
        public int bottom;

        public readonly int Width => (right - left);
        public readonly int Height => (bottom - top);
    }

    [DllImport("User32.dll", SetLastError = true)]
    [return: MarshalAs(UnmanagedType.Bool)]
    static extern bool EnumWindows(
        EnumWindowsProc lpEnumFunc,
        nint lParam);

    [DllImport("User32.dll")]
    [return: MarshalAs(UnmanagedType.Bool)]
    static extern bool EnumChildWindows(
        nint hWndParent,
        EnumWindowsProc lpEnumFunc,
        nint lParam);

    [return: MarshalAs(UnmanagedType.Bool)]
    private delegate bool EnumWindowsProc(
        nint hWnd,
        nint lParam);

    [DllImport("User32.dll", SetLastError = true)]
    [return: MarshalAs(UnmanagedType.Bool)]
    static extern bool GetWindowRect(
        nint hWnd,
        out RECT lpRect);

    [DllImport("User32.dll", CharSet = CharSet.Unicode, SetLastError = true)]
    static extern int GetClassName(
        nint hWnd,
        StringBuilder lpClassName,
        int nMaxCount);

    #endregion
}