Then I'd recommend you don't worry about it.

FAT32 is a file system. It's similar to the FAT16 system used by
Win95, Win3.x and DOS. It can handle larger partitions, which makes it
a good choice for large disks. (It makes more sense to have, say, two
16-GB partitions on a 32GB disk instead of 16 2-GB partitions.)

If you install a new disk - new disks are always VERY LARGE - then
you'll want to use the FAT32 file system for the partitions you create
on it. That will allow you to create partitions larger then 2.1GB.
(Answer "yes" when FDISK asks about large disk support.)

But if your current setup is working for you, and especially if you
are not knowledgeable in this area, don't worry about it. If it ain't
broke, don't fix it!

If you want to learn about it, here's an overview:
http://support.microsoft.com/default.aspx?scid=http://support.microsoft.com:80/s
upport/kb/articles/q154/9/97.asp&NoWebContent=1