Private Declare Function CreateMutex Lib "kernel32" Alias "CreateMutexA" (lpMutexAttributes As Any, ByVal bInitialOwner As Long, ByVal lpName As String) As Long
Sub main()
If 0 = CreateMutex(ByVal 0, 0, "your application title") Then Unload Me
If Err.LastDllError = 183& Then Unload Me
End Sub