--- Letakkan di module
Declare Function GetSystemDirectory Lib "kernel32" Alias "GetSystemDirectoryA" _
  (ByVal lpBuffer As String, ByVal nSize As Long) As Long
'--- Akhir Letakkan di module

Public Function GetSysDir() As String
   Dim boolRetVal As Boolean, lpBuffer As String, nSize As Long
   lpBuffer = Space(255):    nSize = 254
   boolRetVal = GetSystemDirectory(lpBuffer, nSize)
   GetSysDir = StripNullTerminator(lpBuffer)
End Function

Function StripNullTerminator(lpBuffer As String) As String
   Dim I As Integer
   For I = 1 To 255
       If Asc(Mid(lpBuffer, I, 1)) = 0 Then
           lpBuffer = Left(lpBuffer, I - 1)
           Exit For
       End If
   Next I
   StripNullTerminator = lpBuffer
End Function

Private Sub Form_Load()
   MsgBox GetSysDir
End Sub