I don’t own the expansion yet. I only have the base game for black & white 1 and 2. I want to buy it rather than pirate it as I’m a collector.Creature Isle should be installed after the base game. It will install a "CreatureIsle" folder to the "Black & White" folder in the base game's install location. A launcher for the expansion should be placed on the desktop but if not, you can create a shortcut from the CreatureIsle.exe in the install folder. If you have an existing save file in the base game, that will be used and your creature will be brought into the CI.
Hope this helped, cheers!
Edit: In reminding myself of how CI starts, I found that in the intro, the audio may be missing from the sailors as they sail in. They speak once on land but not before. It doesn't break the game but it is odd. If you get your game going, can you let me know if your sailors have audio during the intro? Would like to hunt down those missing audio files, lol.
I found the creature isle expansion! The sailors do speak while on the boat, though the audio is softer then when on land.I can definitely understand wanting a proper copy for the collection. And abandonware is "technically" a no no I suppose, although it is currently the only way to acquire a copy without purchasing a physical copy secondhand. Sadly, the rights for the games are lost between EA and Microsoft so the likelihood of seeing anything proper done with them is slim to none.