when i did my laptop i had XP and sled10 on 3 partitions and a chunk of unalocated space. I installed and let mint just use the unalocated space.
If your windows can see the mandriva partitions try to get rid of them and leave it as unalocated space. this may not work since MS may think it cant handle and ext3 partition or anything not MS.
otherwise live boot and use the GUI partition tool to unalocate the mandriva partitions and then install....
or use fdisk to unalocate the mandriva partitions if you like text mode...
hope this helps.
BTW i did find the partiton tool at install abit limited in creating my own partitions to install to.
