My MacBook Pro will constantly run installer and when I force it to quit in the Activity Monitor, it will automatically open right up again. It really bogs down my computer. Here's what my Activity Monitor looks like:
Running Mavericks.
You must have a unfinished Installer job.
Find out who and stop it there.
In Activity Monitor click to highlight (select) on the in your case Installer file.
The Run the Sample Process for it found here:
In there you will see more information about the process.