shell executor does not open browser

writting as an issue, but I'm not sure if what I want to do is possible. I have set my gitlab-runner in my Windows 7 machine, and for each commit I want to kick off my tests written using Robotframework with selenium for a web application. I set it using shell executor as I don't have any experience with docker and I want the tests to run in a Windows machine.

My gitlab-ci.yml is the following:

stages:
  - test

test:
  stage: test
  script:
  - set PATH=%PATH%;C:/Python27/Scripts;C:/Program Files/Mozilla Firefox
  - cd C:/Users/lestivalet/dev/novoaud/novoaud-angular/test/tests
  - '"C:/Python27/Scripts/robot" -d ../results --variable BROWSER:headlessfirefox -e exception_path -e not_ready "AUD-001 - Carregar Pauta de Audiencia.robot"'

When running the test I get the following error:

WebDriverException: Message: connection reset

I think gitlabrunner shell executor in windows is not being able to open a firefox instance. The same line above running in windows command line works but in shell executor I get the exception.

Is it possible to do what I'm trying to do? Basically, after a commit I want to open the browser (headless or not) and execute my tests.

Thanks