It's probably slow network speeds. I stream HD videos from my desktop to my laptop without an issue when I'm home (Running ASUS RT-N56U router).
I haven't used Windows 8 at all....how are you streaming it? Is there some built in method that makes a wireless access point on the laptop that you connect to? Or is it via a shared folder and you are using your router or something?
I guess either way, do you know the speed of your wireless?