I have an old DOS program that runs fine in a console window under native Windows XP. I've setup a shortcut on the XP machines and selected full screen. When the application runs it opens full screen.

On a Windows 10 with a Hyper-V instance of Windows XP the application is working just fine however no matter what I've tried it runs in a small box. The settings on the shortcut are the same as the ones on the native XP boxes that work.

Any Ideas?