1. Contact email@example.com to ask the new firmware file.
2. Copy the new firmware file to USB hard drive.
Note: The file type of the firmware should be .rom. If it's .zip, please open it on the computer to find the .rom file.
3. Insert USB hard drive to NVR‘s USB port.
4. Go to setting to select the file and upgrade.
If your NVR menu is a blue interface, pls refer to this method: