I have it running as a service on the same OS with Automatic setting and it works ok. I suggest to never run it with a GUI Launcher. It looks like you have run into two Openfire instances running at the same time issue. Your service didn't yet start or you have run GUI Launcher prior starting the service, so your Openfire was running with a GUI process and when you closed it, the server was shutdown. That's why you had to restart the service to make it running again. And the error was probably because the service couldn't connect to a database already opened by the GUI process.
Also i suggest installing it in C:\Openfire to avoid issues with UAC security.