Bonjour Sylvain,
I am using the public Vagrant box on a Windows 10 64-bit laptop - I use it for all of our application testing.
What version of Virtualbox do you have installed? What version of Vagrant?
You can check the Virtualbox version by going into the interface, and under the Help menu, select "About Virtualbox." For Vagrant, use the Windows terminal to navigate to the location where you installed your AtoM Vagrant file, and run:
I was running Virtualbox 5.0-something, and Vagrant version 1.9.8. I have just upgraded each to Virtualbox 5.2.8 and Vagrant 2.0.4, and confirmed that these work. So - first step you can try is checking your versions, and possibly upgrading to the latest version of each dependency.
I don't know if you tried destroying the vagrant box before or after making sure that VT-x was enabled, but if it was before, you might also try that again.
Another thing you can try is launching this directly from the Virtualbox interface. Open the interface and simply double-click on the AtoM Vagrant box - if it works this way, a command-prompt should appear, where you can enter the credentials (username and password are both
vagrant). After that simply open a browser on your host computer and navigate to
http://10.10.10.10.
I've also been doing some internet searches to try to find other suggestions - it seems this is a common issue, not specific to the AtoM Vagrant box, with many possible factors (AKA virtualization is complex). One suggestion I saw was to check the Network adapter settings in Virtualbox. To do so, select the AtoM Vagrant box in the Virtualbox sidebar, and click on the Settings button in the header. In the settings menu, select "Network". For this box, there should be 2 Adapters configured - the first should be NAT, and the second should be your Virtualbox Host-Only Adapter. For both of these, expand the Advanced drop-down, and make sure that the "Cable connected" box is checked:

You can also double-check your Vagrantfile, to make sure it is configured properly. The vagrantfile should be located wherever you first installed the AtoM vagrant box (e.g. wherever you ran the initial vagrant init command). You can open it with a text editor - here are the only lines in mine that are not commented out, for my AtoM 2.5 development environment:
If your vagrantfile does not have some of these lines, you could try manually adding / changing them. We could also try lengthening the time allotted for how long your Windows host machine will try to connect - by default this is 300 seconds, but we could try changing it to 600s by adding the following parameter to the vagrantfile:
- config.vm.boot_timeout = 600
I would then suggest, after saving your changes, that you destroy the box and run vagrant up again.
I hope this helps!