HoMM3 HD is a mod (add-on) for the game Heroes of Might and Magic 3.

Chingis, if this message appears when launching the game through the launcher, then it is obvious that the launcher does not have write permissions to the game folder. Try the following: 1. Run the launcher as an administrator. 2. Or check the permissions for the game folder in the properties, in the security tab. 3. Or the launcher is being blocked by an antivirus (but then the antivirus usually alerts you). 4. As a last resort: go to the _HD3_Data folder, make a copy of the default_ini file, and rename it to _HD3_.ini in the same folder.