function Get-SP2013ProductKey {
$map=”BCDFGHJKMPQRTVWXY2346789″
$value = (get-itemproperty “HKLM:\SOFTWARE\Microsoft\Office\15.0\Registration\{90150000-110D-0000-1000-0000000FF1CE}”).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
}
#Call the function
Get-SP2013ProductKey