That would be:
delete whole partition
- create partition in the unpartitioned space [say 90% of space]
- create another partition in the rest of unpartitioned space [this '10%' should be the size of your RAM]
filesystem you choose now is not important. I highly recommend that you restart windows [don't ask]
Now reboot and start LiveCD installer and when you come to point where you have to select disk for installation, go to advanced (or custom ). That's where you select that '90%' sized partition to be root of your BT,and that 'RAM sized partition' to be the swap partition.
I chose filesystem for root ext2 [was unsure].check filesystems
Then you'll need to find the option to install grub boot manager and select it. Proceed the rest of installation. It worked form me on WinXP with vista boot manager installed but i bet it works with other windows versions.
hope this was helpful