Failed to get Windows Serial Number in Windows 7 - windows

Question

I am trying to get the Windows Serial Number in Windows 7 with my VB6 application. However, it always fails to retrieve it.
SScript.RegRead("HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProductId")
It returns the following error:
Unable to open registry key "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProductId" for reading.
In Win XP, it will be successful to retrieve the serial number. I don't know whether Windows 7 has prohibited a VB6 application to get the Windows serial number.
Please help. Thank you!

Answer 1

It is peculiar isn't it? Try adding this const to your delcarations and OR the value to your open registry call. There is a very good explanation in the answer to KEY_WOW64_32KEY and KEY_WOW64_64KEY.
Private Const KEY_WOW64_64KEY As Long = &H100& '32 bit app to access 64 bit hive
Private Function GetWindowsProductId() As String
Dim strReturn As String
Dim strBuffer As String
Dim lngType As Long
Dim lngBufLen As Long
Dim lngRst As Long
Dim hKeyHandle As Long
lngRst = RegOpenKeyEx(HKEY_LOCAL_MACHINE, "SOFTWARE\Microsoft\Windows NT\CurrentVersion", 0, KEY_READ Or KEY_WOW64_64KEY, hKeyHandle)
If hKeyHandle <> 0 Then
strBuffer = String(255, vbNullChar)
lngBufLen = Len(strBuffer)
lngRst = RegQueryValueEx(hKeyHandle, "ProductId", ByVal 0&, lngType, ByVal strBuffer, lngBufLen)
If lngRst = 0 Then
If lngType = REG_SZ Then
If lngBufLen > 0 Then
strReturn = Left$(strBuffer, lngBufLen - 1)
Else
strReturn = "nothing was returned"
End If
Else
strReturn = "there was an error"
End If
ElseIf lngRst = 2 Then 'the key does not exist
strReturn = "the key was not found"
Else 'if the return is non-zero there was an error
strReturn = "There was an error " & CStr(lngRst) & " reading the key"
End If
End If
GetWindowsProductId = strReturn
End Function