Ok. So I tried just mounting it like you said and couldn't get it to work. So I looked at my fstab and there was nothing about it. So I added a line. Here's my fstab:

/dev/hda3 / ext3 defaults,errors=remount-ro 0 1

proc /proc proc defaults 0 0
/dev/fd0 /floppy vfat defaults,user,noauto,showexec,umask=022 0 0
usbdevfs /proc/bus/usb usbdevfs defaults 0 0
sysfs /sys sysfs defaults 0 0
/dev/cdrom /cdrom iso9660 defaults,ro,user,noexec,noauto 0 0
/dev/cdaudio /cdaudio iso9660 defaults,ro,user,noexec,noauto 0 0
/dev/sda1 mnt/sda1 auto rw,user,exec,sync
# Added by KNOPPIX
/dev/hda1 /mnt/hda1 ext3 noauto,users,exec 0 0
# Added by KNOPPIX
/dev/hda4 none swap defaults 0 0
# Added by KNOPPIX
/dev/hda5 none swap defaults 0 0

But it still won't mount. What am I doing wrong?