You can also use the command line tool "sc" to delete a service (as well as a whole bunch of other things, like set it to manual/auto, stop/start it, etc).

C:>sc deleteDESCRIPTION:        Deletes a service entry from the registry.        If the service is running, or another process has an        open handle to the service, the service is simply marked        for deletion.USAGE:        sc  delete [service name]

Cheers,
Stewart