I haven't used Norton/Symantec in a long time, way too many processes and just bloat in general. NOD32 was one I liked for a while, but now I'm happy using MSE combined with Malwarebytes and a few extras: Process blocker, WiFi Guard, herdProtect, a good hosts file and Windows 7 Manager used to check all the startup apps, services and task manager. All together this takes less memory and CPU than McAfee or Symantec and hasn't let me down yet. Apply updates immediately and watch for any new directories, running processes, startups, turn off remote connections, etc. Even with UAC turned off (It annoys the hell out of me) I've still been issue free for a long time.