Having done this a few times, here's the poop.
Moonrider is mostly right. You can use Windows XP Disk Management (inside Control Panel / Administrative tools) to remove the partition info. However, Windows XP will not allow you to create a FAT32 partition larger than 32 gigs. Note that it will work fine with larger partition, it just wont let you create them. This is a built-in limitation of XP designed to "encourage" you to use NTFS. Why? Because NTFS is less likely to crash, or become corrupted - especially on very large drives.
I have also heard it alleged that FAT32 is supposed to have a slight performance advantage over NTFS, especially if you format the drive with large clusters. But I seriously doubt that the performance advantage would be significant enough to make a real-world difference.
However if you still have your heart set on FAT32, here’s how to do it. First find a Windows 98 system someplace. Make a startup disk, or make a bootable floppy and copy the FORMAT, FDISK, and SYS commands onto the floppy. Then boot your current computer up from the floppy. Now if you just do a DIR you will not see your drives, because a Win98 boot floppy cant read NTFS formatted drives. But run the FDISK command and then you should see your drives – it will show them as being formatted with a “OTHER” file system. First delete the current partition. Then create a new partition. Then reboot the PC with the same floppy and format the drive.
I would recommend that, as a precaution, you disconnect your other hard drives temporarily while doing all of the above. That way you cant accidentally format the wrong drive. If you do disconnect the other drives, be mindful of your jumper settings - you may have to temporarily re-jumper your drive to “single drive”.
By doing this technique I was able to format a 120 gig FAT32 drive that worked fine as a data drive in a XP computer. I just recently replaced that drive with a 250, and this time I formatted as NTFS.
