One computer hogging up all of my bandwith
Alright, so we are with Time Warner Fail, ahem..., *Cable, and we have a network of 3 computers, my computer, and my two sister's computers. My computer does fine in everything when my oldest sister's computer is in the network, even if she watches youtube. But the minute my younger sister connects her older laptop to the network, everything goes AWOL. Ping that's normally under 100 ms goes over 1000 (literally), pages take forever to load, everything is slow as balls. But as SOON as that laptop is disconnected, oddly enough, the bandwith is restored to its normal nature, I need some help with this, it's extremely frustrating and I am about 1 stick away from chucking this thing out of the window, I've had it with Time Warner.
I would guess she has torrents running in the background or something similar. You could download a free monitor tool and install on her laptop to find out which programs are causing the most bandwidth usage. Something like: http://seriousbit.com/netbalancer/
Can google "computer bandwidth monitor applications" to search for others. The basic idea is to find out what's using the most bandwidth on her laptop and if its torrents or some other junk then uninstall the program.
The other route is to just limit her bandwidth all together without worrying about what she has running by setting up QoS on the router which generally will have a feature to limit bandwidth to a computer. You may have to find your router model (Wifi) and google how to setup QoS on it as they all vary to some degree.