by David Monllaó.
You can see the selenium logs in the selenium window but if the problem is that behat is not reaching the selenium instance I suppose behat should throw an exception with info, does it say something or is just failing the tests? I would also say (in case you haven't already tried it) to set CFG->behat_config with wd_host to 127.0.0.1, maybe is an OS problem with permissions between applications, I am far from a Windows expert.