This upgrade file applies for the NLF08TV （8MP） DVR.
You can find your DVR's model number on the label at the bottom of your DVR.
If your DVR's label is lost, please go to DVR's Main Menu - Information - System to take a photo to us, we will send the correct upgrade file to you.
The below is the detail steps to upgrade the DVR:
(1). You needn't open the upgrade file, please directly download the upgrade file
and save it to your U-disk.
(Please save the upgrade file rootfs-3521dv100 in the root directory, not save it under
any other folders.)
Note: it is better to use a 16GB or smaller flash drive with a Fat32 format.
Do not use MICROSOFT EDGE when you do the download, it makes the file to a text file, so the device can't read a text file.
(2). The file's name should be rootfs-3521dv100, can not be have any changes,
if the file's name change to rootfs-3521dv100(1), the upgrade will be failed.
(3). Before starting to upgrade, please unplug the power supply,
then plug the U-disk and mouse into the DVR's back USB ports, and plug the power supply.
(4). It can upgrade automatically as long as it has electricity, the upgrade process need
to last several minutes, please be patient.
After upgraded, Please go to the DVR’s main menu – information – System to check the version.
If the upgrade was failed, we suggest you change another U-disk or USB port to try.
Please don't worry, if this can't help you, please feel free to contact us.