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 Sub CommandButton1_Click()
    Call ShellExecute(0, "open", "", "", "C:\", 1)
End Sub

Mit freundlichen Gr??en,
Andy G.