I can't find it in my tcp/ip configuration because my ISP provides me DNS automatically.
Maybe in Windows there's a file like resolv.conf in linux but i don't remember the location and the name ..

Uff .. i must solve this .. and after .. all will be fine!!

In my resolv.conf there's 2 nameserver and 2 IP .. but my network doesn't work yet.

You must make windows aware of those addresses.
OK. I'll assume you have windows XP (but if you do not the process is not that different).
Click on the "Start" button --> Control Panel --> Network and Internet Connections
Right Click on Local Area Connection (a menu will open up) click on Properties.
A new box will open. Locate a little icon where it says : "Internet Protocol(TCP/IP).
Double click on it (or Highlight and then click the button Properties).
Now another box opens that contains a radio button (among other things) that reads "Use the following DNS server addresses.
In there put the addresses that you found in your linux box.

I just found an example of the web on how to do what I've explainded. Here:
http://www.webhero.org/System/windowsxp_dns.htm

You are now done.

Rick

Ah .. oh my god =.='' i've read to do the contrary: To put in linux the addresses of my internet connection in XP .. sorry =)

Thank you very much..now my network works perfectely ^_^

Bye bye!