First, open the Run dialog (Win + R keys) and type in "services.msc" (without the quotes) and press Enter
Scroll down and locate the "Qualcomm Atheros Killer Service" and right click on it. Select "Stop"
Right click on it again and this time select "Properties"
In the dropdown box for "Startup type", select "Disabled", then click on the "OK" button at the bottom of the window
Next, open Task Manager (right click on TaskBar and select "Task Manager")
Click on the "More details" dropdown (if present)
Click on the "Startup" tab
Scroll down and locate the "KillerNetManager" entry, right click on it and select "Disable"
Finally, restart the system in order for the changes to take affect.