If your recorder is an NVR16-8580 and for some reason, it is not capable to update over-the-air (OTA) to the latest Software Version of V8.1.0-20211019, here are the things you can do.

To check what is your current firmware, access the NVR's Menu then go to System > Information and look for the Software Version.

For units that have a Software version prior to V7.1.0-20180522, check this article first as we need the NVR to be at this firmware before we start: How to do OTA update?

Download the Firmware files

1. Prepare a FAT32 flash drive or USB - it needs to be on FAT32 for it to be read; there is no need for an external HDD as the files are small.
2. Download the firmware from Tech Share , extract the files, and save it to your flash drive.
3. Unplug the Ethernet cable connected to the NVR then reboot.
4. Insert the flash drive to your NVR.

For NVR with Firmware V7.1.0-20180522 or V7.1.0-20180810, follow these steps:

1. Access the Menu and go to Advanced > Maintain then click on Upgrade.
2. Open the Transition firmware folder and select this file: N57XX_V190321V190126V190819V190827V190827V190827.sw and click OK.
3. A confirmation window will appear, click on OK again.
4. NVR will start to update. Make sure not to unplug the USB or turn off the NVR while it is updating.
5. Once done, proceed to the next step below

For NVR with Firmware V8.1.0-20190827, follow these steps:

1. Access the Menu and go to Advanced > Maintain then click on Upgrade.
2. Open the Latest firmware folder and select this file: N57XE_V191128V211012V200923V211019V211019V211019V211014.sw and click OK.
3. A confirmation window will appear, click on OK again.
4. NVR will start to update. Make sure not to unplug the USB or turn off the NVR while it is updating.

Once you have the Software Version of V8.1.0-20211019, you may proceed to this article to get the latest official firmware: NVR16-8580 USB Firmware Update