In case that doesn't work for you (I can't think about why not) then here is more robust api sample:
VB Code:
Option Explicit
Private Declare Function ShellExecute Lib "shell32.dll" Alias "ShellExecuteA" _
(ByVal hwnd As Long, ByVal lpOperation As String, ByVal lpFile As String, _
ByVal lpParameters As String, ByVal lpDirectory As String, ByVal nShowCmd As Long) As Long
Private Const SW_SHOWNORMAL = 1
Private Sub Command1_Click()
ShellExecute Me.hwnd, vbNullString, "test.ini", vbNullString, "C:\", SW_SHOWNORMAL
End Sub