Do you mean there are no USB ports on the back of the computer?
If so you need a pci USB adapter card such as click here
The only type of hard drive that will have USB connectors is an external hard drive.
What is ransomware and how do I protect my PC from WannaCry?
What I learned from my mentor, Oscar-winning VFX supervisor Phil Tippett
Siri vs Google Assistant
Synology invites you to visit them at Insomnia on 26th – 29th August. Book your tickets now and visit Synology.