Are you currently trying to or simply looking to update the features of a working unit? How to upgrade firmware using the Config Tool
: Copy the unzipped firmware file to a USB 2.0 drive formatted to FAT32. Insert it into the DVR's USB port and navigate to System Maintain > Upgrade in the device menu. Download Firmware DVR AHB70xxt8 3521 01B 16Mb Backup rar
If you have obtained the correct firmware, you can typically apply it using one of these common methods: Are you currently trying to or simply looking
: Do not disconnect the power during the update process. A power loss while flashing will often result in a hardware failure that requires an SPI programmer to fix. If you have obtained the correct firmware, you
: Firmware updates are typically distributed as .bin files. If you download a .rar file, you must extract it using a tool like WinRAR or 7-Zip before attempting to use it. General Firmware Upgrade Methods