To not put them in the basement. Try it one more time and heed their install instructions.
I live in a frat house where 20-30 guys are connected to the internet at peak. We have a standard comcast business account with one modem and router in the basement. Obviously, the internet is operating a lot slower because there are so many people using it at once and the wireless signal is pretty weak on the third floor and attic. Is there anyway to make the wireless signal stronger without 1) running a long Ethernet cable to the third floor and 2)having to buy a second modem/account?

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic