Instruction: Answer the given question using the supporting document.

Input:
Question: I bought the WB 1TB HD as suggested. I plugged it in and a DVR error says "NO DISK" on startup. Hard drive works well on the PC.
Document: I'm really impressed that you can get so many features for that money. This dvr does ALL what it suppose to do.The only thing I don't liked is that when I bought it, the headline on the offer mentioned a 1TB hard drive (that is fixed now I see) and of course it not have any drive... just for common sense I realized that for that price should NOT have a drive, so I checked around and find the correct info.
Works better than a Night Owl DVR I bought. Bought another for my parents. My father finds it easy to use and he is not commuter davy.
This is my second DVR from zmodo and this is an upgrade from the 8 channel. Easy installation of the hard drive and its been working well. Deliver was on time.
If you asked me this is a convenience instead of a hindrance. To get it up and running I just used the hard drive from my 8 channel DVR, replaced the screws, and plugged the unit into the wall.However, I must say that the manual is still horrible and if I was setting up remote access for this again or for the first time, I'd be lost. The features are nice for a unit that cost less than $200.
Wow! What a great product! I installed a 1TB SATA HD into the DVR very easily. I turned on the DVR and it was surprisingly quiet. All video images came up very quickly. The controls and remote are all very easy to use. The Zmodo tech support staff were very friendly. If you want your surveillance system set up quickly and at a good cost, this is a must buy!
Excellent DVR! The only downfall is that it doesn't record in D1. But The video quality is still  outstanding. I have 960H HD cameras on this unit and I can see faces clearly. Even when I take a single frame and print it out, the police can recognize who they are (if known of course). I also have 4 ZMD-CNR-BBB23NM CCD 3.6mm cameras. They perform exceptionally well under 15 feet for facial recognition.
For the price, this DVR is amazing. I had to replaced my pc base dvr card with this because I was happy with the results. Will surely recommend this product. Remember you will need a hard drive. My item was shipped fast but the package was missing the housing screws which I am still waiting for the seller service. So far so Good!
Turned the power on (don't forget the in/out switch on the back) and the unit powered up and instructed me to format the hard drive. You do that from the settings mode on screen with a few simple clicks. At the end of this process (5 min), everything froze and I had to restart the DVR (probably normal). I then inputted the settings, including those for each camera and everything just started working.
Hard to get networked into system still having issues directions not written for a novice. You need to know these systems to understand what they are saying. Once you get past that it works pretty good.
Arrived quickly with my Prime membership. Wow, never dreamed this 16-ch Zmodo DVR would be so easy to install. It came with case top unattached along with the separate hard drive I had ordered so I did not have to remove the case. I installed the hard drive by hooking up two cables and inserting four small provided screws (60 seconds). I attached the case with the screws provided.
Answer: You have to format the disk with the DVR, it cannot read the windows file format, The instructions tell you how to format the disk in the dvr, then reboot and your set.