How to change partitions/volumes in external hard drive?

I have had a 60G external hard drive that has worked flawlessly for 2 years
with both my desktop computer running Win98SE, and my newer laptop with
Windows XP. This external drive was formatted with FAT 32 and NO PARTITIONS
for all 60G. Because I have a Lot of music files and digital pictures, I
have filled up the 60G drive, so bought an IOGear 160G external drive. This
drive arrived partitioned into 6 partitions, of 20-32G sizes. This is
completely wrong for how I want to use the drive. All my mp3 programs
requires the library to be all in one volume, so I need 60-80G all in one
volume just for music. IOGear support says that Windows XP does not allow
volumes any larger than 60G in FAT 32. (This seems crazy since my older
drive is all one volume and is FAT 32.) Does anyone know how I can collapse
these volumes onto one larger one (say 80-90 G) and have it in a format that
both my Win98SE system and my WindowsXP laptop can both access?