|They are all running programs. Sometimes the programs themselves have an option to put an icon in the tray or not.|
If you just want them out fo sight then right click the Start Button, go to Properties, Taskbar tab then Customize. They can be changed from Always Show to Always hide. They will then temporarily appear if you clich the arrow on the taskbar near the clock.
msconfig (as already given) is a means to stop stop the programs running if all else fails.
If they are totally unwanted then uninstall the appropriate programs but you will need the software if you ever need them again.
Always pop back and let us know the outcome - thanks