Before you download anything, check the sticker on the bottom of your router. Installing firmware for a V1 or V2 on a V4 unit will permanently "brick" the device. Cool Ideas [OpenWrt Wiki] TP-Link Archer C5 v4

Check the label on the bottom of your router. It will specify the region (e.g., "Archer C5(US) Ver:4.0"). Visit the Official TP-Link Support Page: Global/UN: TP-Link Archer C5 V4 Support United States: TP-Link Archer C5 V4 (US) Support

: Scroll to the Firmware section and download the latest build (typically the top-most entry with the most recent date).

Arjun downloaded the file: Archer_C5v4_up_booster_1.13.0.bin . He stared at it. He’d heard the horror stories: someone downloads the wrong file for the v2 hardware, flashes it, and their router becomes a glowing paperweight.