How do I install a windows service that runs as an administrator?

Question

I've written an installer that installs a windows service (A) that needs to start/stop another service (B). However, when A tries to start/stop B, I get this exception:

System.InvalidOperationException: Cannot open MyService service on computer '.'. ---> System.ComponentModel.Win32Exception: Access is denied

The installer installs the service as a local service, and it requests admin rights via the UAC pop-up, which I grant. I've also added an app.manifest file to the service that is set to ask for admin rights:

Yet I'm still getting that error.

This is how I start the service (stopping is the same, except it calls Stop, of course):

using (Mutex mutex = new Mutex(false, "MyServiceLock"))
{
    mutex.WaitOne();

    if (ServiceExists(serviceName) == true)
    {
        using (ServiceController serviceController = new ServiceController(serviceName, "."))
        {
            serviceController.Start(); // this line throws the exception
        }
    }

    mutex.ReleaseMutex();
}

Why might access to this service be denied?

Answer 1

A service cannot ask for a UAC elevation. It sounds to me that the UAC prompt you describe is actually requested by the installer, not the service. Services normally run with a very privileged account already, LocalSystem by default. Do make sure that you configure the service to use such a privileged account, not a restricted user account.