By the way, share your game setup – do you have the "Complete Collection" or the "Gold Collection"? That would make things clearer. Also, surprisingly, it's often better to install a pirated version – they almost always have built-in compatibility with XP, which, as I mentioned, is very helpful.
Справочник по НоММ-4 http://handbookhmm.ru/pamyatka-dlya-heroes-iv.html
Памятка по НоММ-3 http://handbookhmm.ru/pamyatka-dlya-homm-iii.html
и HotA http://handbookhmm.ru/vyishla-obnovlennaya-pamyatka-dlya-homm-iii-hota.html