Add-Type @"
using System;
using System.Runtime.InteropServices;
using System.Collections.Generic;

public class Win32Helper {
    public delegate bool EnumWindowsProc(IntPtr hWnd, IntPtr lParam);

    [DllImport("user32.dll")]
    public static extern bool EnumWindows(EnumWindowsProc enumProc, IntPtr lParam);

    [DllImport("user32.dll")]
    public static extern uint GetWindowThreadProcessId(IntPtr hWnd, out uint lpdwProcessId);

    [DllImport("user32.dll")]
    public static extern bool IsWindowVisible(IntPtr hWnd);

    [DllImport("user32.dll", CharSet = CharSet.Auto)]
    public static extern int GetWindowTextLength(IntPtr hWnd);

    [DllImport("user32.dll", CharSet = CharSet.Auto)]
    public static extern int GetWindowText(IntPtr hWnd, System.Text.StringBuilder lpString, int nMaxCount);

    public static List<IntPtr> GetProcessWindows(uint processId) {
        List<IntPtr> windows = new List<IntPtr>();
        EnumWindows(delegate(IntPtr hWnd, IntPtr lParam) {
            uint id;
            GetWindowThreadProcessId(hWnd, out id);
            if (id == processId && IsWindowVisible(hWnd) && GetWindowTextLength(hWnd) > 0) {
                windows.Add(hWnd);
            }
            return true;
        }, IntPtr.Zero);
        return windows;
    }
    
    public static string GetWindowTextStr(IntPtr hWnd) {
        int length = GetWindowTextLength(hWnd);
        if (length == 0) return "";
        System.Text.StringBuilder builder = new System.Text.StringBuilder(length + 1);
        GetWindowText(hWnd, builder, builder.Capacity);
        return builder.ToString();
    }
}
"@

$ppts = Get-Process -Name "wpp", "POWERPNT", "wps" -ErrorAction SilentlyContinue
foreach ($p in $ppts) {
    Write-Host "Process $($p.Id) $($p.ProcessName)"
    $hwnds = [Win32Helper]::GetProcessWindows($p.Id)
    foreach ($hwnd in $hwnds) {
        $title = [Win32Helper]::GetWindowTextStr($hwnd)
        Write-Host "  HWND: $hwnd, Title: $title"
    }
}