[BitBucket user: Alain Mazy]
[BitBucket date: 2017-05-19.15:54:47]

To evaluate:  The Orthanc service launches Orthanc as a separate process.  It's very likely that this process is killed by the shutdown since Windows does not realize that it's related to a service.

=> we should check if there is a flag that could prevent windows from killing this process.