james090 wrote:Laptop Wifi Adaptor : Broadcom Netlink Gigabit Ethernet
That says Ethernet and doesn't give a Model name which doesn't help.
Control Panel - System and security - System - Device Manager - Network Adapters.
Expand the list and look for a Wireless Adapter and note the name and model number.
Double click it and select the advanced tab.
Look for a property called something like 802.11n/ac Wireless mode and note the setting. See if you can change it to 802.11ac which would make it choose AC over N which is what you want.
Look also for a property called Preferred Band and set it to Prefer 5GHz.
After you've done this disable and re-enable WiFi and using the method used before check to see if you are now connecting with AC rather than N.
Even if you are stuck on N changing it to 5Ghz should help.
If it hasn't changed then reboot the laptop.
The router should easily be new enough to support AC.
No need to login at this point.
You can login using Ethernet or WiFi.
Instructions may be on the router itself including a password which is different to the WiFi password.