No-CD patches are used to avoid having to put the game CD in each time you want to play. Developers do not officially support no-cd patches (or cracks) as they are often used for pirated copies. "Black and White 2" is no different.
Please only use a no-cd patch for "Black and White 2" if you own the game. I highly recommend using Game Jackal (which can be used with 99% of games) or virtual CD software.