To update the BlackVue DR550GW-2CH firmware, you must do the following:
1) Connect the microSDHC memory card to the computer via the adapter, make a backup copy by copying the contents to the computer and format it in FAT32 format.
2) Download the firmware to your computer from the official site https://www.blackvue.com/downloads, at the time of this writing, the latest Russian version was 2.002 (2014.06.18). Before flashing, you must make sure that the language on the one that is installed and the new one is the same, otherwise you must first localize to the appropriate one.
3) Unpack the archive with the firmware and move the BlackVue directory to the memory card.
4) Insert the card back into the DVR and wait for the update procedure to complete.
It is recommended to update the firmware only on the version above (do not update the old ones).