With the main components in place we can now fit the DVD drive and hard drive.
You will need to remove the metal plate and case blanking plate from the bay which is going to hold your DVD drive.
Carefully slot the DVD drive into its bay and secure with screws. 
Connect the power cable from the main power supply to the back of the DVD drive.
Now plug the data cable (SATA cable) into the back of the DVD drive and then into the socket on the motherboard.
The hard drive is fitted in a similar way. Usually the case will have a special bay designed for a standard Desktop PC 3.5” hard drive.
Locate the bay and then slide the hard drive into place, secure with screws.
Tightening hard drive screws.
Now again connect the power from the main power supply, then the data cable to the motherboard.
