Under this (and I guess all the WIN32:: stuff) are of course the Windows APIs. If you really want to get into all this stuff and play with Windows internals, then an MSDN subscription is well worth the money. (Before you ask, no I don't work for M$).
I pulled all the return codes from the service control API's and there's a lot more info in there too if you need it.
The WIN32::Eventlog stuff is very useful too. I've used it to scan machines for certain errors and to log important messages centrally for my scripts. Although this module doesn't seem to be able to read logs on other machines it can be used to log failures in your scripts which can be them checked centrally by the administrator using the standard OS tools.
in reply to Simple WIN32 Service Test