A couple of days ago my laptop started making my wifi very slow. My normal internet speed when tested on speedtest.net is about 16mbps. When my laptop is off and I check on my tablet it's still that speed but when my laptop is on it makes the wifi go between 0.1 and 1.5mbps. The weirdest part is that it doesn't affect computers connected directly to the ethernet.
At first I thought it was a virus so I formated the hard drive and reinstalled a clean copy of windows 10. That didn't work so I updated all the drivers and that still didn't work. I haven't changed internet providers and I've had this laptop for a long time so I have no idea how to fix this.