Windows 7: Problems with wireless network in win7

I'm having Problems with wireless network in Windows 7, it was all after i transported my pc from Europe to south America, i mention this cause perhaps we can consider a hardware issue, but it doesn't seem so.
I connect to the wireless network with my Mac Book Pro without any problem, but with my Windows 7 pc i have problems of different kinds, now it tells me that I'm connected and have internet but i try to open any webpage and i don't have internet.
Now just before i posted this i started having internet, it's intermittent, when in my mac it runs smoothly.
help?

If you says you are online but the browser won't connect it usually has to do with the TCP/IP stack or winsock, you can try resetting winsock and the TCP/IP stack and see if that helps.



Follow these steps to use the reset command to reset TCP/IP manually:

1. To open a command prompt, click Start and then click Run. Copy and paste (or type) the following command in the Open box and then press ENTER:
2. At the command prompt, copy and paste (or type) the following command lines one at a time and then press enter.
3. netsh winsock reset catalog (reset winsock entries)
   
4. netsh int ip reset reset.log hit (reset TCP/IP stack)
5. Reboot the computer.

You should also check the network you are connecting too and see what type of security it uses.
Windows 7 likes using WPA2 with AES encryption.

done, didn't help. Still intermittent (or just disconnected) and good in MacBookPro

Most likely a weak signal or the wireless router you are trying to connect with is using security or encryption that Windows isn't set up to use. You should check the wireless profile and make sure the settings are the same as the wireless connection.