Hi Breno You can check the wired devices wether can get the correct speed. After all, when the devices is connected to the router directly, the testing result will be more acurrate.

If your wireless clients are connected to a Range Extender, then their MAC address will share the same first 6 digits of the MAC address on C5400. Only in this way your wireless clients can access...

Make sure that your HDD hasn't password. And you can try to use \\192.168.0.1 to access it.

I doubt that your other devices take up your bandwidth. You can try to connect your PC only and play the game.

Samuel_8935 wrote Hi there! I have 300 Mb/s speed by LAN but my router cuts it and I get only 40. Changing channel etc doesn't help. Where should I look for? Regards The WAN port of TL-WR841N...

Make sure that the PVID of port 33 is 2.