Internet problem

[*]hi i am using a windows xp pro and my internet doesnt work.
[/list] i have tried every possible thing i can think of.
i am on my old compaq and the internet works fine, now i know that the modem and router is working fine…
the odd thing is that when i use linux on my pc the internet works but when i use windows is does not work at all…
can someone please help me