Cannot connect to Windows 10 in VirtualBox

I would like to run Windows 10 in a virtual machine. Since I'm new to virtual machines, I followed Techno Dad Life's tutorial on https://www.youtube.com/watch?v=Me7McYocVM0. Only with Windows 10 64bit, instead of Ubuntu.
This seems to work fine, I installed VirtualBox, followed the steps in the video and have started the VM. In the preview window I can see the first screen of the Windows installation. See attachment 1.

However, I cannot connect to the machine. When I click on the server port, as shown in the video, and click the resulting .rdp file, an error message pops up after a few seconds. See attachment 2.
I tried VNC client, but this tells me 'The connection was refused by the computer'.

I am probably forgetting something or making a mistake somewhere. Would be very thankful for any tips, hints or outright manuals

Bert-Jan

@Nefertitii; Thanks for the info. Although access to shares wasn't t he problem in this case, I do struggle with that on a Windows laptop from a friend. I'll check out the HOWTO.

@geaves; Thanks, but that didn't work for me. Problem persisted. After some more tries I (finally..) noticed that the VM had me connect to it at 127.0.0.1. I tried replacing that IP address by the local IP address of the OMV server en that worked. Probably obvious in hindsight.. I'm new to VM's

So; solved. Although not yet as useful as I'd hoped, until now. The VM is slooooow, which should not surprise me that much, since it is now running on mechanical HDD's, something I haven't done with OS's for years. And I do have some issues with the mouse, but I'm still checking that out.

Thanks for both your help!