How do I change the Windows XP partition to open up some space on the hard drive? Without reinstalling WinXP.

What hard drive space is needed for a basic Linux Ubuntu installation?
   For partition swap, the minimum between 2GB and the size of RAM
   For system, 2.7GB, but as you need data (including installation process) I advise at least 4GB.
How do I access the new partition?
   Whats you needs?
Previous new version of Ubuntu said I did not need to create another partition, but install failed without it.
   It's the case with Wubi installation, but I dislike it (perhaps because I'm not able to manage it). If you want to avoid creating a new partition, have a look at virtual machine, like Virtual Box. Except for 3D (but there are few 3D games in Linux), you have same performances than native system (be careful to have enough memory, at least 1GB).

If you have more then 2Gb RAM then set swap to the SAME amount as your RAM. If you have less than 2Gb RAM then allocate DOUBLE your RAM amount as swap
You will need at LEAST 6 ot 7Gb for your root partition (or '/' as it's known). You can then use the rest as /home. All the partitions can be primary as you will have 4 partitions and you are only allowed 4 primary partitions. Make them all be ext4 and you will be fine.

Yes wubi has a LOT of shortcomings and I personally do not advise it to be used. It also suffers from the shortcomings of NTFS fragmentation as the disk image is stored in NTFS.

Problem solved.
Would appreciate pointer to same topic conversations.

How do you mean??