The patch is designed to work with a vanilla English version of the game, patched to 1.0.7.4. NO MODS SHOULD BE INSTALLED. The patch most likely won't be compatible with them.
The CD check has been removed as well, no point in it after all these years.
Although it's not obligatory, it's advised that you start a new game. Some fixes (e.g. Kraka-Tur journal) won't work with old saves.
