This may be evident to some people, but I was a little surprised that my first attempt at it failed.
If you ever want to divide a drive into two partitions, one formatted as Mac OS Extended (HFS+) and the other as FAT32, and to be able to access the FAT32 partition from Mac OS X and Windows, just make sure you set the FAT32 partition as the first one on the drive when you partition it with Disk Utility.
To be able to use it under Windows, you also have to make sure the partitioning scheme is set to Master Boot Record (MBR).
If you set the HFS+ partition as the first one, Windows won't be able to see the FAT32 partition and will tell you that the disk has to be formatted.
I tested this with a USB flash drive under Windows 7 Pro and under XP Pro, and both only recognized the FAT32 volume when it was the first one.
I did not test this with a hard drive, with a different bus than USB, or under Windows Vista, but I assume these cases follow ...
If you ever want to divide a drive into two partitions, one formatted as Mac OS Extended (HFS+) and the other as FAT32, and to be able to access the FAT32 partition from Mac OS X and Windows, just make sure you set the FAT32 partition as the first one on the drive when you partition it with Disk Utility.
To be able to use it under Windows, you also have to make sure the partitioning scheme is set to Master Boot Record (MBR).
If you set the HFS+ partition as the first one, Windows won't be able to see the FAT32 partition and will tell you that the disk has to be formatted.
I tested this with a USB flash drive under Windows 7 Pro and under XP Pro, and both only recognized the FAT32 volume when it was the first one.
I did not test this with a hard drive, with a different bus than USB, or under Windows Vista, but I assume these cases follow ...