Info
OS (Host): Windows 10 Pro
OS (Guest): Windows 7 Ultimate
Version: 6.1.32
Problem:
When I send Ctrl+Alt+Del signal to the guest, it would show the Ctrl+Alt+Del screen. But it has black stuff on it. When I hover my cursor on the buttons, the black stuff around the buttons disappear. But the remaining black stuff will remain there. When I click the shutdown button, it would show the Shutdown screen. But like the Ctrl+Alt+Del screen, it has black stuff on it. When the text changes, again, it will disappear but the remaining black stuff will remain there. Same thing goes for the User Account Control screen. When Windows needs me to give permission on a specific app, it would display a pop-up window. But, again, black stuff appears. When I move the window, the black stuff disappears but the remaining black stuff, will remain there. Oddly enough, when I close out of those screens, the black stuff disappears. And same for the remaining black stuff. But it will reappear again.
Images
User Account Control Screen:
Ctrl+Alt+Delete Screen:
Shutdown Screen: