So here's the setup, I have three computers connected to a WRT160N router. 2 wired and 1 wireless. My dad, sis and I. When all three computers are on, the internet is normal. When my dad is downloading movies, the internet gets extremely laggy and ping rockets sky high from 20 all the way to 1k+. But when my sis is downloading movies, internet remains normal. So the problem is my dad's computer. Is there any reason on why it's just one computer that's downloading movies make everyone's internet so slow?