So what your asking for is a windows service that cannot be terminated until Windows is closed down, then you want to know if there is a way to attach a program to that service so that it cannot be terminated as well?
I could be wrong, but I doubt if windows would give you the opportinity to create and attach a program to a service which would make it impossible to kill, unless you pulled the plug. i'm guessing you would have to write some sort of extra program to monitor the current one so that it could restart it, if it got closed down.