Wondering if I have multiple products that may be slowing down computer

Please help.  I had downloaded an update for Norton internet security 2012.  But I notice that in addition to Norton internet security 2012 files, I also have listed separate files for Norton 360 and another separate file that  just states Norton.  These might have been there previous to Norton internet security 2012.  I don't know but I was wondering if I can just delete or uninstall these other files since all I think I need is the current one I'm using: Norton internet security 2012.  Wouldn't all these help to slow down my computer?

Thanks