I did the step according to the help of PureCoverage
1.Add the PureCoverage product and cache directories to your system PATH environment variable. (For a system service, it is important to add these directories to your system PATH, not just your user PATH. Some systems require you to be an administrator to change these variables.)
2.Reboot your machine so the system uses the new value.
3. Instrument the program without running it. For example, from the command line, type: coverage /Run=no /Out=service_app_pure.exe service_application.exe.
4.Use Regedit.exe to edit the ImagePath registry value for the appropriate service under the key: \HKEY_LOCAL_MACHINE\System\CurrentControlSet\Servi ces and change the name to the instrumented program. For example, service_app_pure.exe, using the programí»s full path name. (Some systems require you to be an administrator to change these keys.)
5.Double-click the Services icon in the Control Panel, select the service you want, and then click Startup.
6.In the Service dialog, select Allow Service to Interact with Desktop. (This way, PureCoverage is visible while you run the service.)
7.Select Manual, and then click OK.
8.In the Services dialog, click Start. This launches the instrumented service program, which launches PureCoverage, if needed.

But the purecoverage could not lauch, when I start the service.