Answer:

To install a hard drive, follow these steps:

Step 1: Power off the NVR and open the casing by removing the screws.

Step 2: Slide off the casing.

Step 3: Place the 3.5 inch SATA hard drive into the drive bay.

Step 1: Secure the hard drive using the screws provided.

Step 2: Connect the SATA data and power cables to the drive.

Step 3: Put back the casing and reinstall the screws.

Note: Connect the NVR to power outlet again, once the system starts up,  navigate through the system menu to format the drive to make it ready for recording.