Wish I knew. All drivers up to date and my system should be quite clean of any unwanted software. The symptoms are that the mouse still moves and while in game has the in-game cursor. Once I Ctrl-Alt-Delete or Alt-tab to try to kill Ashes, I get a white screen that persistently hides any other programs, including the Task Manager, that I try to bring to the front. The Start Menu still works, so I use it to sign out, which kills running programs.
If you have any ideas to help me diagnose the problem I'd try it.