You say that the DB has stopped running.

Can you view the event log on the computer and see if there are any relevant messages (Event Viewer)?

Also, from the Task Manager, can you verify that the ProntoDataService.exe is a running process?

If it is not running, Start->Run->Service.msc and start the Pronto Data Server (Service). If it stops again, have a look at the event log and see if you can ascertain a cause.