As kubuntu is booting from the cd, it should not matter how the partitions vista made look like, yes?
You need free disk space to install any linux distro to. That means the other OS you have can not have all the disk space in partitions. It does not matter if the partitions have a lot of free space or not. If windoze has all the space, you will have to shrink the partitions and create free space, at least enough to install Kubuntu, if that is the distro you want to install.
I don't know why Kubuntu is " freezing " there could be some hardware related issue.