.. Click Start, then go to Run, then type in: msconfig
.. Click on the Startup tab at the top, this will show a listing of programs
that auto start when your computer is first booted. If you uncheck the box the
program will no longer auto start and sit in your system tray /notification area
when you boot. You'll need to reboot before this takes effect.
Another way to do this would be to go to the program that is in your system
tray/notification area and you may find the settings to remove them from the
auto start, most programs have this listed in the properties section.
To help you identify what is required and what isn't, perhaps these links will
assist with that. Make sure you don't disable anything that is important!
http://www.pacs-portal.co.uk/startup_content.php
All about disabling programs at startup
http://www.answersthatwork.com/Tasklist_pages/tasklist.htm