No, compact disks are not partitionable, all you can do is separate files onto folders when recorded. Folders will be the partitions.
Use a partition manager like GParted or the one on the Vista setup CD to expand the NTFS partition. You cannot expand the partition while Windows is running on it.
When you boot from the install CD, indicate which partition you want Ubuntu installed on.
There are a number of programs you can buy to facilitate this. Both a partition and a CD are possible, but the partition is a bit riskier. I have not done this in several years, but I ran into problems with what to do when I decided I did not want the partition anymore. Anyway, try looking at buying a program. The CD method is sometimes called imaging the harddrive or ghosting it.
Use your Ubuntu CD. Find a program called "GParted" or "Gnome Partition Editor". Click on your XP partition and click "Resize" and make it smaller. Then, do the same with your Ubuntu partition, and drag it until it fills the space left by XP.
The best way to completely remove any Operating System is to delete the partition that it is on. Your best bet is to download Knoppix and burn that to a CD, then Boot from the CD and find the partitioning tool and delete the partition that the Operating System is on.
Partitions should be removed using a partition manager. If you have a Ubuntu live CD, then you can run partition editor from there. If you don't, then you should install a partition editor in your main operating system.
Insert of your Ubuntu CD, then using GParted, delete your Windows partition and resize your Ubuntu partition until it fills the space left by the deleted partition.
Make system back up on CD's or USB stick with reboot action included. Either split hard disc into two partitions and save important files in separate partition or save important files on CD (Scan with anti-virus and anti-malware programs on computer all and if needed clean the partition or CD on different computer). Format the computer. Insert system back up CD or USB and reboot. Once rebooted upload files that you have saved from CD or separate partition.
If there is one partition in a hard disk and one CD device then the default drive letter assigned is D. Else, If there are two partitions in a hard disk and one CD device then the default drive letter assigned is E. Else, If there is only one partition in a hard disk and two CD devices then the default drive letters assigned to both CD devices are D and E.
The root directory is indicated by a "/'. You can navigate to the root directory using the command 'cd /'.
Factory recovery partition, Windows CD installation and Network installation
If you are sure you want to delete the windows xp partition then you can use the windows CD to do the job.Boot the machine with the CD in the drive and you should get the option to format the drive.Just be sure this is what you want as you will lose all your data stored on the drive.