function Get-ProductKey {        $map="BCDFGHJKMPQRTVWXY2346789"     $value = (get-itemproperty "HKLM:\SOFTWARE\Microsoft\Windows NT\CurrentVersion").digitalproductid[0x34..0x42]      $ProductKey = ""      for ($i = 24; $i -ge 0; $i--) {       $r = 0       for ($j = 14; $j -ge 0; $j--) {         $r = ($r * 256) -bxor $value[$j]         $value[$j] = [math]::Floor([double]($r/24))         $r = $r % 24       }       $ProductKey = $map[$r] + $ProductKey       if (($i % 5) -eq 0 -and $i -ne 0) {         $ProductKey = "-" + $ProductKey       }     }     $ProductKey }

PS> Get-ProductKey VKTXG-GXXY3-W97QP-GP4PV-XXXXX