Manually delete a windows service

You can 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 delete
DESCRIPTION:
        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]