dialog message for multiple instances of application executable

[anealc]

Hi there,
I have an application which is only allowed to run on Windows once. If the
user attempts to invoke a second instance this second instance shows a
message to the effect that the program is already running, before switching
to the original instance.

My question is that is there a Microsoft standard for this behaviour? The
only Microsoft app that I can think of that does this is Media Centre, but
that doesn't show any message.
Thanks
Aneal