To best of my knowledge,
nothing can prevent an application process from killing by a user having sufficient privileges and the process handle.
Moreover, one can use Sysinternals utility PsKill which can kill
any local or remote process unconditionally, even if it can destabilize or completely screw up the system, see
http://technet.microsoft.com/en-us/sysinternals/bb896683[
^].
Why doing that?
—SA