Activate the Finder Application and select 'Go/Connect to Server' from the menu or type Command-K. The following window will be opened. Type in the address of the windows server prepending to it the string smb:: in the example below this is smb:olympe.epfl.ch.

On the dialog window that will appear please enter your login credentials. In the case of olympe.epfl.ch or other server at EPFL, the username will be IC\your_gaspar_username, and the password will be your gaspar password.