I would hazard a guess that in order to use the wifi hotspots you need to use the app as their are other protocols and security services running in the background on top of a simple username and password. That being said you would be expected to be able to connect on a window 10 laptop which is also a mobile device so have you had a look to see if there is a windows app you can download to establish the connection just like the android/ios version?
Update: Just done a very quick google, look at the last post in this thread
https://community.virginmedia.com/t5...3844090/page/2