Assisting Boot Camp Assistant I decided to "give a hand" to Boot Camp and partition my drive, setting aside a FAT32 partition for installing windows (through Boot Camp) in the future.

Can one do this or does Boot Camp Assistant need to be handed a single-partition drive and do the partition itself?
From the Boot Camp FAQ:


  Boot Camp Assistant works only with an Intel-based Mac that has a single hard disk partition


Boot Camp won't work with your multiple partitions, unless the partitioning was done by Boot Camp itself.

You'll probably need to undo the partition to use Boot Camp, or use one of the many ways discussed online for installing Windows without the usual Boot Camp installation steps.