slow dl speed

Hello, I just installed the latest build 10/18, and I am having very slow speed to dl, for upload it seems fine, I reach as high as 50 kbps, but I should be dling at 100+ kbps, as I used to do on windows and the fastest I have being able to do so is 8 kbps. Could someone help? if this is a thing of set up in airport I would like some help....Thanks.