You can switch to windowed mode by pressing F4. But, your desktop has to be set to 16-bit (I think) color mode before this will work.
then, Why does Heroes of Might and Magic 3 keep crashing?
If our game crashes frequently (especially when entering the town view), please try different compatibility modes, starting from Windows 95 (you can change these in the Properties of the game’s shortcut, under the Compatibility tab).
hence,
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