param([long]$Hwnd, [string]$Out = "w.png")
Add-Type -AssemblyName System.Drawing
Add-Type @"
using System; using System.Runtime.InteropServices;
public class P {
  [DllImport("user32.dll")] public static extern bool GetWindowRect(IntPtr h, out RC r);
  [DllImport("user32.dll")] public static extern bool PrintWindow(IntPtr h, IntPtr hdc, uint f);
  [DllImport("user32.dll")] public static extern IntPtr GetWindowDC(IntPtr h);
  [DllImport("user32.dll")] public static extern int ReleaseDC(IntPtr h, IntPtr dc);
  [DllImport("user32.dll")] public static extern bool BringWindowToTop(IntPtr h);
  [DllImport("user32.dll")] public static extern bool SetForegroundWindow(IntPtr h);
  [DllImport("user32.dll")] public static extern bool ShowWindow(IntPtr h, int c);
  public struct RC { public int L,T,R,B; }
}
"@
$h = [IntPtr]$Hwnd
[void][P]::ShowWindow($h, 9)   # SW_RESTORE
[void][P]::BringWindowToTop($h)
[void][P]::SetForegroundWindow($h)
Start-Sleep -Milliseconds 400
$r = New-Object P+RC; [void][P]::GetWindowRect($h, [ref]$r)
$w = $r.R - $r.L; $ht = $r.B - $r.T
if ($w -le 0 -or $ht -le 0) { Write-Host "bad rect"; exit 1 }
$bmp = New-Object System.Drawing.Bitmap $w, $ht
$g = [System.Drawing.Graphics]::FromImage($bmp)
$hdc = $g.GetHdc()
# PW_RENDERFULLCONTENT = 2 (captures DWM-composited content incl. many D3D windows)
$ok = [P]::PrintWindow($h, $hdc, 2)
$g.ReleaseHdc($hdc)
if (-not $ok) {
  # fallback: screen copy of the (now foreground) window rect
  $g.CopyFromScreen($r.L, $r.T, 0, 0, (New-Object System.Drawing.Size($w, $ht)))
}
$bmp.Save($Out, [System.Drawing.Imaging.ImageFormat]::Png)
$g.Dispose(); $bmp.Dispose()
Write-Host "saved $Out (${w}x${ht}) printwindow=$ok"