Dell OptiPlex 755 - Manual (Page 68)

3. Remove the computer cover (see Removing the Computer Cover ).
4. Remove the optical drive (if your configuration has one). See Removing an Optical Drive .
5. Disconnect cable from the existing hard drive.
6. Remove the existing hard drive from the computer (see Removing a Hard Drive ).
7. Remove screws from the existing hard drive and install them on the new hard drive.
8. Carefully slide the new hard drive into the upper bay until it clicks into place.
9. Insert reconnect the cable to the drive.
10. Locate an unused SATA connector on the system board and attach a data cable from the second hard drive to the SATA connector.
11. Replace the optical drive (if your configuration has one). See Installing an Optical Drive .
12. Replace the computer cover (see Replacing the Computer Cover ).
13. Turn on the computer.
14. Enter system setup, and update the SATA port option under the Drives option list (see Entering System Setup ).
15. Exit system setup, and reboot the computer.
NOTICE: Always connect the data cable to the SATA1 connector when installing a second hard drive.
1 data cable 2 hard drive system board connector