Public Declare Function GetWindowsDirectory Lib "kernel32" _
    Alias "GetWindowsDirectoryA" _
    (ByVal lpBuffer As String, ByVal nSize As Long) As Long

Public Function GetWinDir() As String
    Dim windir As String  ' receives path of Windows directory
    Dim SLength As Long  ' receives length of the string returned

    windir = Space(255)  ' initialize buffer to receive the string
    SLength = GetWindowsDirectory(windir, 255)  ' read the path of the Windows directory
    windir = Left(windir, SLength)  ' extract the returned string from the buffer
    GetWinDir = windir
End Function