When I'm on my laptop, every time I watch a YouTube video, stream music, or download music to my itunes my mom's laptop gets kicked off the internet until it's done. But when I'm just on Facebook or other websites or listening to music on itunes that's already downloaded everything's fine. Any idea what's wrong and how to fix it?

My guess is it's a quality of service issue, meaning the network switch is giving your machine priority over your mom's machine because you're using more bandwidth.

I'm guessing you have a wireless router. Is it an older model? Like, 802.11b? I'd first go on the manufacture's website and look for a firmware upgrade.