Adding Ubuntu to WinXP dual boot
 

I have found directions for installing Ubuntu after WinXP, but the partitioning instructions require functions that are not presented to me in the Sherline Ubuntu installation. I have an 80 GB Windows partition but my Ubuntu installer won't let me resize it. Is this a "feature" of the Sherline installer that would not exist in some other download?

My only choices are
1) Use the entire disk
2) Use the largest free space (there is no free space)
3) Manual .... but manual has no "resize" function

There is no "resize" function in your installer, yes, that's correct.

To resize a Windoze partition, you need to unscramble sectors on that partition, first. That process is sort of an art; booting into non-graphical mode, turning off all the swap space, multiple reboots, etc., etc. Are you at all familiar with what I'm saying?

Then use the 'parted' utility from Ubuntu. 'qtparted' is the program I prefer. Once you've resized the partition, you can begin your Ubuntu install.

backup your windows partition before you resize it or tears could ensue

Before you do anything to windows from Ubuntu, make sure you have the backup and you have defragmented all the partitions.

I have no experience with these things. I defragged but am left with a few files at the top end.

I do not use windows since a very long time any more.
Out of my memory there are 2 possibilities :
1) you have not turn off the swap file of windows before defrag or page file as they called it
2) They do have files with you can not be moved.

I rebooted with no swap file and the files in the upper end of the partition did not move in defragmenting. They are not immovable file types.

You can do the partitioning you need from the Ubuntu LiveCD, which comes with GPartEd preinstalled. Be sure to defragment Windows first.

This is not unexpected. There are often sectors left up high on the disk. The trick is to re-run the defragment process *REPEATEDLY*, booting in between trials. Boot into safe-mode, no swap, no graphical interface, etc, etc.

I have spent as much as two days defragmenting a Widoze disk before I re-partition with qtparted (or some other variant), with lots of defrag attempts.

Repeat, recapitulate, redo, and then do it one more time. You might see movement in those troublesome sectors.

That was too tedious. I ordered a new HD for $60, installed Windows on half and had a clean half for Ubuntu. I have my dual boot now, but I can't get the wifi to fly under Ubuntu. Seems that there's always another obstacle!

If you have time, you don't need money. If you have money, you don't need time. Seems to work that way in all endeavors : )

Congratulations on your dual-boot machine!

I have used the GParted live cd for this kind of thing before.