I just upgraded to Windows 10 (everything was fine before when I was on Windows 7 64bit) and now each time I alt-tab, the right half of the screen goes dark, everything is squeezed into the left and the colors are screwed up. The buttons are still in their original positions. Does anyone else have this issue? It happens with all three games.

My solution ( for mm8 ) .

go to "*****\GOG Games\Might and Magic 8"
right clic on MM8.exe

Modify "compatibility mode" as me

Windows R "regedit"

See the "attached image"

Alway run the game with MM8.exe
After "alt - tab" if Graphical glitches press F4 wait and F4 again.