I tested it on a 32-bit Windows 7. It works perfectly, even without any compatibility modes (although it works with them too). Maybe it works differently on 64-bit. But I still can't figure out what the problem is. Especially with such an uncommon report.
The operating system is 64-bit. I launch Heroes through the HD executable, and immediately a window pops up saying "Heroes of Might and Magic has stopped working, searching for a solution," and then this window appears.
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