vfat mount error

I talked my friend, who is a big Windows fan, to trying linux.

He has 2 drives, and he has linux on hdc1 and win98 on hda1.

When we set the box up, I mounted hda1 so he could get to his
windows files from linux.

Now when ever he tries to mount hda1 with type vfat he gets
a message:

$ mount -t vfat /dev/hda1 /mnt/cdrive

mount: fs type vfat not supported by kernel

He said is was working and then all of a sudden this started
to happen. No rebuild has been done.

Does anyone have any idea what is causing this and how to fix it?

Thanks

John Gorman