I never installed because from my experiences with programs like these they only mask problems and many times create more problems. For those problems that came up with Symantec software I was able to find fixes on their web site.
Symantec products are no different.
Norton Antivirus loads auto protect, a definitions alert and e-mail proxy program. Norton Utilities will load a couple of background utilities. Norton Clean Sweep will load 2 utilities. I have disabled all of these utilities from loading automatically. The most recent version of Symantec is Norton 2001.