go to START -> RUN and type MSCONFIG and than in startup tab, u can disable programs. I am not sure about adding programs.
Right. Adding to the Start menu's Startup group is the easiest way. Otherwise, you can add an entry to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run or HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run in the registry.