Get free Winpatrol from same domain. Its free and allows you to disable and then kill if app is active (prompt option). It also allows you to configure Scheduled tasks, services, startups (disable or delete), tracks changes in associations and much more. Very low resource and CPU bandwidth used. No reboot needed to activate changes. It is very good. Another is Mike Lin's startup mgr.
I recommend you uninstall Norton and stick with MS Antimalware with Winpatrol and use a sandboxed browser like Chrome Opera or IE9 and use a browser addon such as WOT (Web of trust, & No script ) for additional security consideration.
I consider a well tuned PC with minimal but adequate security one to boot with < 20 processes shown in same tab of taskmgr in XP after boot. 25 for Vista and 30 for Win7.
Alo Check > Computer> Manage> Scheduled Tasks> Microsoft > and look for execute on startup ...according to the huge list of categories listed ....