When working with NT services, Coverage Validator can't access the data in the stub due to security differences between itself (an application) and your service.
To overcome this problem, the stub sends all the coverage data to the user interface when your application stops (e.g. you stop it from the service manager or the control panel, etc).
This allows the user interface to display the coverage data after your service has completed, but it's not unreasonable that you might want to see coverage data while the service is running.
Coverage Validator provides an on-demand utility to retrieve updated coverage information when you want it.
or use the Ask stub for coverage data icon on the Session toolbar.
There will be a short pause whilst coverage data is sent from the stub to the user interface.