No thats find, just download the FW first to the PC, I actually prefer loaded FW with out the modem connected. Just do this, when you do the last factory reset, power off the router after it comes back to ready. Then go and place the router back in it's spot. Or you place the router back in it's spot after the FW is applied and the router comes back to ready, Then do the factory reset then. Just make sure that ALL other devices are turned OFF or disconnected from the router while you factory reset and set up from scratch and let the router settle for about 10 mins. I'd power OFF the modem while you do the update, then power back on after place the router, then power ON the router.