How to find and kill an installer that autostarts at boot time Asking on behalf of a child who doesn't remember if/when some application was updated and required a restart to complete the installation.

OSX 10.8.5 , MacBook Pro.   Here's what happens:  when rebooting, a dialog window comes up with the "package" icon and asks "Continue with Install?"  and one must select either 'yes' or 'abort'.  

If 'yes' is selected, then a process owned by the user runs forever, incidentally consuming up a lot of RAM.  Whether 'yes' or 'abort' is selected, the same dialog comes up on the next reboot.  

In Activity Monitor, the process is just called "Installer."

Things we know were not initiated: any system upgrade. 

My offspring vaguely remembers starting to update "some app" which was later deleted from the machine.  Assuming that's the case, this installer appears to be hung trying to get to files that don't exist.

So, in any case, is there some file I can delete that will stop the installer from starting up on reboot?  If there is something I can do to provide more info on what/where this Installer app is, let me know and I"ll post it up.
Besides the Login Items (Open the Users &amp; Groups pane of System Preferences),
try this.

In Terminal, type 

ls ~/Library/LaunchAgents


You will see your "personal" launch agents.

To see all the currently loaded agents, type this:

launchctl list


If you can identify the one you don't want, use the unload option:

launchctl unload ~/Library/LaunchAgents/whateverItIsYouWantToUnload