WWW Publishing Service Stopped Unexpectedly With Event ID 7031

We have been getting the EventID 7031 errors ever since we
installed SP 3. We have been searching for any possible
solution, but not much luck.

We are running Windows 2000 server with IIS 5.0 (No
indexing services installed), and SP4. Every now and
then, we have the 7031 for IIS Admim, SMPT and WWW
services stopped without any apparent reason. We noticed
that the Event Viewer logged those 7031 errors when all
the hosted sites were stopped.

I wonder if a script can be written to detect the status
of the sites and restart the IIS if they are stopped. If
so, please provide information on that as I have never
done something like this before.