Amazon.com: HP 793739-001 System Board (Motherboard) - ProDesk 400 G3 MT : Electronics
HP ProDesk 400 G3 Microtower Desktop Computer W5X53UT#ABA B&H
HP Desktop PC ProDesk 400 G3 (V0C44UT#ABA) Intel Core i3 6th Gen 6100 (3.70GHz) 4GB DDR4 500GB HDD Windows 7 Professional 64-Bit (available through downgrade rights from Windows 10 Pro) - Newegg.com