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
 
Call ShellExecute("", "Open", "C:\Update.exe", "", "", 1)