Get a live cd & you can do it!!
start installation with installer cd follow the installation till partition editor create new partition (better going with NTFS)then the partition editor will be automatically refreshed and you can see your new partition ,then quit the installation and restart your pc.
preferable distro's for this method:mint,ubuntu
don't use unknown distros if you are vary much newer to linux!!!
if you are using backtrack (or something like that)try this to get your root password::
2)ping IP adress appeared in ifconfig
4)you will get root password in the list given
5)then use it in gparted