If you are using a NVR/THDR without a harddisk installed, the system will show you a warning message upon boot.
The warning look like this:
To get rid of this, you can of course install a harddisk. But you can remove the warning, from the GUI like this.
1. Login to the NVR / THDR
2. Navigate to 'CONFIG' > 'EVENT' > 'Abnormality'
3. In the dropdown menu, select 'No Disk'
4. Remove the check mark, marked with a red box below (disable the alarm)
Another option is, to remove the 2 check marks in 'Show Message' and 'Buzzer'.
5. Remember to click 'App' and 'OK'
6. Reboot the NVR / THDR ('OPERATION' > 'SHUTDOWN' > 'SYSTEM REBOOT').
The warning is no longer shown.