If your files are on another windows box, use Gnomba (easy-to-use frontend for samba) to browse your windows boxes. All you have to tell it is the possible range of IP addresses and it will happily scan your network and tell you what's on it.
If your files are on a fat or ntfs partition on the computer you've got Mandrake on, you can mount it (but you can't safely write to ntfs) by doing:
su (type password)
mkdir /mnt/windows
mount /dev/hdd5 /mnt/windows (replace /dev/hdd5 with your windows partition)
Now all your files are in /mnt/windows.
If you get an error on the last step, you're probably missing kernel support for the filesystem. Look for and install the ntfs package, do modprobe ntfs as root and retry the last step.