So as expected, Kubuntu 12.10 Live Boot didnt boot up. I had to disable all options-F6-noapm, noapic, nolapic etc, to get it to boot.

Once booted, I reused my /home partition, and wiped / and /boot from my Debian system.

Once installed, on first boot, it showed me a broken graphic and hung up. Ctrl-F1 to open the terminal didnt work either.

So download the latest NVIDIA Ubuntu package (it ends in .run)

Boot to the Ubuntu recovery environ-Grub2>Ubuntu Advanced>Recovery

Choose the menu option to drop to shell

Check if root and home file systems are mounted. If not mount them.

Run an fdisk -l and see file systems

on Trying a mount command, it told me that fstab is probably incorrect.

So see the mount with cat /proc/mounts

I found that / was read only so remounted as rw

mount -o remount,rw /

Now I can run the NVidia package.

Edit: Still didnt boot with kernel.

Finally, booted to recovery, installed the following linux kernel headers:

apt-get install linux-headers-generic linux-headers

Now, install the proprietary Nvidia drivers:

K Menu>Applications>System>Additional drivers

Choose any of the proprietary drivers