You can try to put another 2GB RAM or search about this. Probably your Mac Mini support 4GB of RAM.[0]
Some Macbooks and Mac Minis "up to 8GB" support 16GB. [1] [0] http://eshop.macsales.com/shop/mac-mini/ [1] http://www.gizmag.com/macbook-pro-2011-models-support-16gb-of-ram/18135/
