Laptop Causing Weird LAN Lag To All PCs

I have a WiFi in my home, when this laptop is under normal load, say like streaming a 360p youtube video, all the computers in my home will experience a huge lag and it becomes impossible to surf or do any internet activity (even the causing laptop itself will experience huge pings). The weird part is that the lag is at the LAN level, it is not related to my internet bandwidth. Because when I ping my local router (192.168.2.1) with other PCs during the lag period, I get 1000-4000 ms. However, it is usually 1 ms. I tried doing a stress test on one of my normal laptops by downloading at maximum speed, the problem did not occur, there was no lag, all my PCs did not encounter that lag and I still get 1 ms when pinging the router. It is only this laptop that when it starts downloading, my network will be flooded.

Another related problem with the laptop is that every time I log off then log in and try to reconnect to my network, It will not allow me, I will have to click on the windows diagnose problem and it will be fixed saying "Problem with wireless adapter or access point".