Go to the main menu--advanced--storage and check if there is the hard drive and its status is normal.
If there is nothing on the storage or the status is not normal, it means something is wrong.
Please try troubleshooting methods below.
1. if the status says unformatted, click format.
2. If the hard drive is not from us, please make sure your hard drive meets all requirements in the link below. http://support.annke.com/kb/index.php?action=artikel&cat=10&id=24&artlang=en.
Please make sure your hard drive is for surveillance use, not for PC use,
3. Open the cover of DVR/NVR. ?Uninstall and install?HDD?for several times. Hers is method http://support.annke.com/kb/index.php?action=artikel&cat=11&id=24&artlang=en
4. Install hard drive and put hard drive close to your ear to check if you can hear some noise. One hour later, use hand to touch the hard drive to check if it is warm. If you can not hear any sound and surface of the hard drive is not warm, it can prove hard drive is not even powered up. Please share our result.
5. Unplug DVR or NVR from power and plug again.
6. restore DVR or NVR to factory setting.
7. Change an adapter of DVR.
8. Try a spare DVR or HDD if you have.