Q: Installer maxing out RAM usage; Freezing computer

Whenever I start up my computer, it will slow down and tell me that I don't have enough free disk storage (I've checked, and everything's alright in that regard).  The RAM usage will spike right before and this message pops up after I hit 200mb RAM free.  I've opened up Activity Manager, and saw that Installer, for some odd reason, kept taking as much RAM as possible.  Every time I boot up, I have to force a quit in Activity Manager on Installer for my computer to function.

OS X El Capitan

MacBook Air (June 2014, 1.4 GHz Intel Core i5, 4GB 1600 MHz DDR3