Never attempt to flash your router's firmware over a wireless Wi-Fi connection. If the wireless signal drops for even a fraction of a second during the flashing process, the router will become permanently corrupted and unusable. Unplug your computer from Wi-Fi. Take an RJ-45 Ethernet cable. Plug one end into your computer's LAN port.
If you experience frequent Wi-Fi drops or have to restart your router daily, a firmware bug is often the culprit. Updates stabilize the ADSL2+ handshake process and improve wireless signal retention. dlink dsl124 firmware new