It was shown that:

• It is possible to write interactive service with forms. The Synchronize method of TNtServiceApplication is used to place all forms into main application thread and avoid thread safety problems;
• Forms of interactive service are corrupted by logoff/logon;
• The TsvSurviver component successfully protects service forms from corruption;
• The TsvSurviver component successfully protects message windows and commonly used dialogs too. It is enough to place it onto form surface and it will work;
• The tray icon feature can be added to interactive service;
• It is necessary to restore the tray icon after interactive user re-logons;
• The TsvLogonSensor component successfully detect logon event which allows to re-instantiate the tray icon and do any other necessary actions.

Complete code of this example in it`s final state is available here (zip, 3.5kb).