If you have a FAT partition and you would like to take a look at Linux while doing it, get the Knoppix cd image in a mirror near you, burn it and set your bios to boot from cd-rom.This CD boots directly to memory, doesn't require any installation, is easy to use and has lots of interesting stuff
Beware that Linux can't write on NTFS partitions!
Or you can use explore2fs like aa said, but it's only for ext2/3 I think.
However, first I recommend that you ask them what filesystem they used and post it.