I recently tried to update the software (firmware) on my old TP-Link TD-854W because the unit was running and kept dropping the ADSL connection. Here is what I learned.
If you're using a range extender alongside your router, you can follow similar steps on the to keep that device updated as well. update software in tplink td854w hot
If you successfully updated the software in your TP-Link TD-854W Hot but still face problems: I recently tried to update the software (firmware)