Use an Ethernet cable, not WiFi, to connect your PC to the Sagemcom router. WiFi disconnections during firmware flash are catastrophic.
: Because Sagemcom typically manufactures hardware for service providers (e.g., TalkTalk, Vodafone, T-Mobile), the most reliable firmware files are hosted on the ISP's official support pages. Sagemcom Firmware Free Downloads
If you have a firmware file (typically a .bin or .img file) and need to install it, follow these general steps: Use an Ethernet cable, not WiFi, to connect