XP internet

i have 2 hard drives one with ubuntu and the other with windows. i havnt used windows in a while, but on ubuntu 7.10 the internet works flawlwssly, and when i use windows, it never connects. i checked the ip, and windows sees it, and its the same as the one ubuntu sees. i tried renewing the ip, but it keeps failing. i also did the microsoft internet confiure test, and it told me to check the cables and turn on and off the modem for 3 mins so i did all that, and it still didnt work. any advice? oh, and just for info, i cant dual boot, so i switch between hard drives (the reason i never use windows as much) thanks in advance.