Only use the TP-Link Archer C5 V4 Download Center to ensure the file is legitimate and matches your region. How to Update Your Archer C5 V4 Firmware Method 1: Local Manual Update (Most Common) Download for Archer C5 V4 - TP-Link
Verify that your router is truly V4 . Look at the sticker on the bottom of the device; it must say "Archer C5(UN) Ver:4.0" or similar. tplink archer c5 v4 firmware update
Never update over Wi-Fi. A momentary wireless drop can corrupt the firmware. Connect your PC directly to one of the router’s LAN ports using an Ethernet cable. Only use the TP-Link Archer C5 V4 Download
A failed update can "brick" your router, making it unusable. Follow these safety steps first: tplink archer c5 v4 firmware update