It is recommended that you use a surveillance-rated hard drive or security camera hard drive to record. Surveillance-rated hard drive or security camera hard drive is used for 24/7 local storage of surveillance video footage. 

If you bought a DVR or NVR system with a hard drive from us, our security camera hard drives are pre-installed inside the DVR or NVR system. 

If you bought a DVR or NVR system without a hard drive, our DVRs and NVRs don't support the external hard drive, you need to buy a professional surveillance internal hard drive to install.

It is not recommended that you purchase a desktop hard drive. A surveillance hard drive or security camera hard drive is more durable, advanced, and reliable than a desktop hard drive in a lot of ways.

A surveillance hard drive spends more than 95% of its time writing. The hard drive firmware (software embedded in the chip) is designed to handle surveillance applications since its optimized for fast data writing.

Here a list of surveillance HDD manufacturers:

• Toshiba_(S_300)
• Seagate_(SkyHawk)
• Western Digital_(Purple)

(Like 3.5 inch Seagate Skyhawk, Samsung or Western Digital (purple))

Note: The max hard drive size supported by our DVR system is 6TB.

We suggest you buy Seagate 1TB or 2TB hard drive.

You can follow up the below video to install and remove the hard drive:

Some related problems for your reference: 

 Hard drive not recognized by DVR/NVR system

        What if the hard drive can't be formatted by DVR/NVR system?

If this can't help you, please feel free to contact us.