New computer is messing up my network?

I just bought my wife a new HP Pavilion dv6t with windows 7 ultimate. Ever since I added it to my wifi network, everything else has been acting up. Like netflix just shutdowns and my PS3 will log off me out. I don't believe it's the router because it can handle plenty more devices than what I have. So i'm a little confused as to what's going on. So if anybody can help, thanks.

A side thought, could too many of the same frequency devices cause interference between everything else?