To find out how to change a particular program’s startup settings, look at the program’s “help” offerings, or do an internet search. For example, Skype, an internet telephony/chat program, can be disabled via Tools → Options → General Settings → deselect "Start Skype when I start Windows". As another example, Dropbox, a file sharing and storage program, can be disabled by right-clicking the system tray icon (the icon in the windows toolbar near the clock), clicking the gear-shaped icon, then selecting “Preferences…” Startup items can be deleted manually though your computer’s “regedit” program.  See an overview of this process here. Editing your computer’s registry should only be done as a last resort and only if you know exactly what you are doing.
قم بتغيير إعدادات البرنامج نفسه للتعامل مع إعدادات بدء التشغيل لنفسه. استخدم سجلّ registry لحذف عناصر بدء التشغيل.