One Joystiq reader found out the hard way, telling us, "My only hard drive with any storage space left on it is FAT32, and has resisted attempts to reformat. I discovered this hidden system requirement after buying The Witcher 2, downloading it, and attempting to install it this morning."
CD Projekt confirmed the situation to us this morning. Community manager Andrzej Kwiatkowski said, "Yes, we can confirm that The Witcher 2 on Windows systems only works on NTFS-formatted drives." Kwiatkowski further explained that the design is due to the limitations of the older FAT32 system. "FAT32 can't handle any file bigger than 4GB, and one of TW2's files has the size of 9GB."