well your pc looks office machine.
you can keep
Primary Hard Drive: 120 GB Intel 530 Series SSD - single drive
Data Hard Drive: 1 TB hard drive – 32MB cache, 7200RPM, 6.0Gb/s - single drive
get new CPU, MOBO, RAM, Cooler, GPU, Power Supply, Case, probably Operating System
what is your monitor resolution and how many FPS do you want to have?