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BenowiBonro, here are two points:
1) Heroes of Might and Magic IV doesn't work properly with newer DirectX versions. Many problems and lags can stem from this.
2) Heroes of Might and Magic IV doesn't work properly with multi-core processors. As far as I understand, Windows 8 and 10 have a different way of managing cores, which is detrimental to the game. In my case, it would completely freeze every 10-15 minutes. You can use processes to set it to use only one core, and then the game will run relatively stably. Although freezes will still occur. I don't know how to fully optimize it.
But at least 90% of the problems are due to the two points mentioned above.
1) Heroes of Might and Magic IV doesn't work properly with newer DirectX versions. Many problems and lags can stem from this.
2) Heroes of Might and Magic IV doesn't work properly with multi-core processors. As far as I understand, Windows 8 and 10 have a different way of managing cores, which is detrimental to the game. In my case, it would completely freeze every 10-15 minutes. You can use processes to set it to use only one core, and then the game will run relatively stably. Although freezes will still occur. I don't know how to fully optimize it.
But at least 90% of the problems are due to the two points mentioned above.

Барон "Vampires"
Отдай свои прошлые сны,
В сомненьях себя обрети,
В бешеном танце душа кружится!
Не думай, что будет потом,
Здесь и сейчас мы живем,
Стань хоть на миг сам собой, слышишь!