procedure TForm1.Button1Click(Sender: TObject); 
var 
  ProcessID : DWORD; 
  ProcessHandle : THandle; 
  ThreadHandle : THandle; 
begin 
  ProcessID := GetCurrentProcessID; 
  ProcessHandle := OpenProcess(PROCESS_SET_INFORMATION, False, ProcessID); 
  SetPriorityClass(ProcessHandle, REALTIME_PRIORITY_CLASS); 
  ThreadHandle := GetCurrentThread; 
  SetThreadPriority(ThreadHandle, THREAD_PRIORITY_TIME_CRITICAL); 
end;