Updating firmware can often fix certain issues with routers/modems/network hardware which can lead to improved performance overall - so it's definitely worth checking! Purchase a separate Wi-Fi extender: If none of these solutions resolve your problems with sluggish wifi speeds on the WNDR4300 router, it may be necessary to purchase a separate Wi-Fi extender - especially if you're located in an area where there isn't adequate cellular coverage for optimal streaming or gaming performance!