I am also using Windows 10 (in a VM) and have been recently updated. I don't understand the folder issues that Don explains, mine does not seem to behave that way. However from time to time when Windows gets updated funny things happen on my VM and things that once worked no longer work (I go into panic mode and backup everything (all my works in progress for both scenarios and maps, I always have a few I am working on
), thank the Lord for the Cloud drive thing) and then it 'magically' starts working again.
Any way I am running the game (both actually) just fine in W10, you'll have to do as Andy says in your settings but if your partial to full screen you can use the border-less gaming thing. I use it, I like the experience for both the games and the extended editor and don't mind alt+tabbing back and forth (it does help that I have two monitors, and the VM is on one and my host O/S is on another, makes it easy to use the extended map editor in one monitor and use the vehola tool in a browser in the other monitor).