If you look for your product key on a Windows Server 2008 R2,
you probably retrieve a key with “BBBBB-BBBBB-BBBBB-BBBB-BBBB”

You can use the following function, save it to a powershell file and run it.

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function Get-WindowsKey {
## function to retrieve the Windows Product Key from any PC
param ($targets = “.”)
$hklm = 2147483650
$regPath = “Software\Microsoft\Windows NT\CurrentVersion\DefaultProductKey”
$regValue = “DigitalProductId”
Foreach ($target in $targets) {
$productKey = $null
$win32os = $null
$wmi = [WMIClass]”\\$target\root\default:stdRegProv”
$data = $wmi.GetBinaryValue($hklm,$regPath,$regValue)
$binArray = ($data.uValue)[52..66]
$charsArray = “B”,”C”,”D”,”F”,”G”,”H”,”J”,”K”,”M”,”P”,”Q”,”R”,”T”,”V”,”W”,”X”,”Y”,”2″,”3″,”4″,”6″,”7″,”8″,”9″
## decrypt base24 encoded binary data
For ($i = 24; $i -ge 0; $i–) {
$k = 0
For ($j = 14; $j -ge 0; $j–) {
$k = $k * 256 -bxor $binArray[$j]
$binArray[$j] = [math]::truncate($k / 24)
$k = $k % 24
}
$productKey = $charsArray[$k] + $productKey
If (($i % 5 -eq 0) -and ($i -ne 0)) {
$productKey = “-” + $productKey
}
}
$win32os = Get-WmiObject Win32_OperatingSystem -computer $target
$obj = New-Object Object
$obj | Add-Member Noteproperty Computer -value $target
$obj | Add-Member Noteproperty Caption -value $win32os.Caption
$obj | Add-Member Noteproperty CSDVersion -value $win32os.CSDVersion
$obj | Add-Member Noteproperty OSArch -value $win32os.OSArchitecture
$obj | Add-Member Noteproperty BuildNumber -value $win32os.BuildNumber
$obj | Add-Member Noteproperty RegisteredTo -value $win32os.RegisteredUser
$obj | Add-Member Noteproperty ProductID -value $win32os.SerialNumber
$obj | Add-Member Noteproperty ProductKey -value $productkey
$obj
}
}

Get-WindowsKey

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