Refurbished: Dell OptiPlex 780 USFF Desktop Intel Core 2 Duo E8400 3.0GHz 4GB DDR3 RAM 250 GB HD DVD-RW WiFi Bluetooth Microsoft Windows 10 Pro - Newegg.com
Upgrading Ram in the Dell Optiplex 760 - YouTube
8GB (2X4GB) Memory Ram Compatible with Dell Optiplex 780 Dt/Mt/Sff Desktops by CMS A69 at Amazon.com