$proc->SetPriorityClass($priority)
Sets the priority class of the object to $priority. The priority can be one of the following:
IDLE_PRIORITY_CLASSA process whose threads run only when the system is idle.
NORMAL_PRIORITY_CLASSA process with normal scheduling.
HIGH_PRIORITY_CLASSA process that performs time-critical tasks that must be executed immediately.
REALTIME_PRIORITY_CLASSThe highest priority process, even preempts OS threads.