Why does Ares slow down the internet connection on other computers in my home network?

When my girlfirend runs ARES on her laptop, my PC's internet connection dramatically slows down. She is connected wirelessly to the router and I am connected by a lan line(CAT5). We have Road Runner high speed internet. She is only downloading like 3 or 4 sonags at a go, so I can't for the life of me figure out why that would dramatically effect my connection. Ironically, I am positive that this is the case because the second she completely exits ARES or her downloads complete, my connection works normally again. If any one has a suggestions to solver this or an answer to why this is happening, I would greatly appreciate it. Thanks in advance.