You don't state what OS you use, but if Windows at least then try and install CCleaner and look at the startup entries it finds. You can then disable/delete useless stuff.

NOTE: Some startup entries are necessary for your computer behaving properly. So use common sense what disabling or deleting entries. I would recommend rather disabling entries instead of deleting them, unless you are quite sure they won't make your system FUBAR.

Download CCleaner 3.02.1343 - FileHippo.com

You can find the startup entry manager under the tools tab in CCleaner.