Posts from Heroes 3 issues under XP or Vista.
Fixed the Service Pack 4 issue in Heroes3 The Shadow of Death (Buka).
Windows 10, CD emulation - UltraISO.
1. Installed DirectX from Microsoft and verified that DirectPlay is enabled.
2. Copied the contents of the CD to the HDD.
3. In the _setup folder on the HDD, set the compatibility to Windows XP sp2 for the setup.exe file in its properties.
4. Ran setup.exe as an administrator.
The main thing: without step 2 (copying to HDD), it constantly complained about Service Pack 4, and any other manipulations, such as editing the registry, did not help.