In order to format in FAT32, the partition cannot be larger then 32GB. So with your 250GB drive, you'll end up having around 7 partitions.
You can read more about that here:
http://support.microsoft.com/default...b;EN-US;314463
What you may be able to do, is have one or two FAT partitions, and then format the rest in NTFS. This may be able to allow you to use the drive on your friends system, while not having so many partitions.
I'd try to create one 30-32GB partition, format with FAT32. Then attempt to access the drive with your friends computer.