1. Click the Start menu button on the Windows taskbar.
2. Click Run... on this menu.
3. If the computer is holding a current IP address, type 'cmd' (without the quotes) in the text box that appears. A command prompt window appears on the screen.
4. Type 'ipconfig' (without the quotes) to view the status of the computer's IP address(es).
5. If the computer is holding a current IP address, type 'ipconfig /release' to let go of the address.
6. Type 'ipconfig /renew' to obtain a new IP address (whether or not the computer is holding a current address).
I took it from http://www.tomshardware.co.uk/forum/23807-18-access-router-internet
It solved my problem :)