Private Type OSVERSIONINFO
    dwOSVersionInfoSize As Long
    dwMajorVersion As Long
    dwMinorVersion As Long
    dwBuildNumber As Long
    dwPlatformId As Long
    szCSDVersion As String * 128
End Type

Private Declare Function GetVersionEx Lib "kernel32" Alias "GetVersionExA" (lpVersionInformation As OSVERSIONINFO) As Long

Private Function IsVista() As Boolean
    Dim tOSVERSIONINFO As OSVERSIONINFO
    tOSVERSIONINFO.dwOSVersionInfoSize = Len(tOSVERSIONINFO)
    Call GetVersionEx(tOSVERSIONINFO)
    IsVista = (tOSVERSIONINFO.dwMajorVersion > 5)
End Function