Marie, take a look at this simple guide.
       http://netsquirrel.com/msconfig/

 You shouldn't do anything in msconfig unless you absolutely had to.  Too many these days use it for the wrong purpose and not for troubleshooting which is all it should really be used for.

 To remove items from the systray the first place to look is Start > Programs > Startup folder, which are only shortcuts to the actual executable.  Anything that is truly not necessary or wanted by yourself to run at startup can be deleted from the startup folder.  As mentioned they are only shortcuts.  If you want to run the app at any time you can double click the execute file or use Start > Run by either typing the full path or browsing to and selecting the file.

 Any items in the systray that are not in the startup folder can be stopped from running at boot by opening the app and checking the menus on the menu bar for any Options ( or similar name).  Look in the options for any selections you can check/uncheck stating "Start with Windows", "Run at startup" or anything similar.  To stop any program at the moment in the systray, right click the shortcut icon and see if it has an option to Exit/Quit.