errors continue at startup

Greetings all;Well it’s getting more and more interesting as I learn how to use my o/s. I originally started out with the error;msin has caused an error in RICHED20.DLL;also included in todays startup was error;SYMTRAY has caused error in SYMTRAY.EXE;also EXPLORER ERROR . As instructed I run MSCONFIG and selective startup.where do I go from there?It was suggested that I remove startup pgms that are not needed.By observation of my system tray yesterday and today; I notice that the Norton Systemworks icons are showing each utility that is running in the background;including CleanSweep Smartsweep & CleanSweep InternetSweep;as well as Norton Antivirus and GoBack.These icons are shown today at startup.Yesterday the “N” was displayed for all the utilities;alsoin the system tray was the GoBack icon and of course the volume control.I know where to look for the problem but can’t understand why I continue to get the same errors. thanks jerry