About Linux and filesystems:
Linux accesses filesystems by mounting them to folders. One needs to be mounted at '/'.To access any filesystem, you need to mount it to a folder. The installer puts a ramdisk at '/', so you don't need to worry about that. To access another filesystem, you need to mount it at a folder in the ramdisk. Then, when you look in the folder, you will see the contents of the ramdisk. Example:
*assuming you're using an installation floppy, want to access the isos from the hda5 partition*
mkdir /mnt/win_c
here we make a folder called 'win_c' in the /mnt direrctory
mount /dev/hda5 /mnt/win_c -t vfat
mount hda5 to win_c
cd /mnt/win_c
plunge in
ls
see what's inside
cd /mnt/win_c/save/mandrake
go to the isos
Remember that Linux is case-sensitive. I am assuming you are using a floppy to access the isos on your hd. The various different distributions of Linux have different ways of installing from isos on an hd, so be sure to search the Mandrake web site on how to do it.
Edit:
See this:
http://www.osnews.com/story.php?news_id=5577
The 'fdisk -l' command lists partitions. I doubt 'C:' is hda5, Windows likes to be first, like hda1