get-win7-productkey.vbs

' VBS Script to get the Windows(R) 7 Product Key from a PC's registry.
'
' Save the VBScript as "getWin7Key.vbs" somewhere on your Windows7 PC.
' Now, when you double-click the local script file an alertbox pops up
' displaying the product key stored in the machine's Windows registry.
'
'http://www.howtogeek.com/124286/how-to-uninstall-your-windows-product-key-before-you-sell-your-pc/
'http://goo.gl/x3eO0x

Set WshShell = WScript.CreateObject("WScript.Shell")

KeyPath = "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\DigitalProductId"
MsgBox ExtractKey(WshShell.RegRead(KeyPath))

Function ExtractKey(KeyInput)
    Const KeyOffset = 52
    i = 28
    CharWhitelist = "BCDFGHJKMPQRTVWXY2346789"
    Do
        Cur = 0
        x = 14
        Do
            Cur = Cur * 256
            Cur = KeyInput(x + KeyOffset) + Cur
            KeyInput(x + KeyOffset) = (Cur \ 24) And 255
            Cur = Cur Mod 24
            x = x -1
        Loop While x >= 0
        i = i -1
        KeyOutput = Mid(CharWhitelist, Cur + 1, 1) & KeyOutput
        If (((29 - i) Mod 6) = 0) And (i <> -1) Then
            i = i -1
            KeyOutput = "-" & KeyOutput
        End If
    Loop While i >= 0
    ExtractKey = KeyOutput
End Function