To check what is your current firmware, access the NVR's Menu then go to System > Information and look for the Software Version. For a NVW-800, the latest Software Version is v8.1.0-20210720

Before you try the following procedure, read this article first: How to do OTA update?

If you are unable to use the automatic update service to update the recorder, you can use the following procedure to update manually.

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 file HERE and save it to your flash drive.
3. Unplug the Ethernet cable connected to the NVR then reboot.
4. Insert the flash drive to the top USB port of the NVR while the mouse will be connected to the bottom USB port as shown in the diagram below:
   
5. Access the Menu and go to Advanced > Maintain then click on Upgrade.
6. Select the file: H7004_V210616V210616V210624V210720V210720V210720V201120V210616V210616V191235.sw and click OK.
7. A confirmation window will appear, click on OK again.
8. NVR will start to update. Make sure not to unplug the USB or turn off the NVR while it is updating.

NOTE: If updating the firmware via Menu fails, use Swann Security VMS on a Windows computer. Follow Firmware update for OS 5 recorders via Swann Security VMS (Windows)