If I understand you correctly, you want to restore the original XP
partition to its original size. If The XP partition can be rebooted
successfully, then it should be pretty easy.

Boot your live Lubuntu disk and access GParted. You can delete the
partition(s) created by the failed Lubuntu install (I'm assuming there
are two, including the swap partition). Looking at my dual boot
configuration with GParted, I see a Windows partition (/dev/sda3) and an
extended partition containing my Ubuntu partitions (/dev/sda5 and
/dev/sda6). Both of thee are part of /dev/sda4, which is the extended
partition you want to remove.

First, delete the swap partition /dev/sda6 and then delete the Lubuntu
partition /dev/sda5. Now you should have an extended partition which is
all free space. You should be able to delete it now, leaving unallocated
(free) space to the right of your Windows partition.

Now you can resize (expand) the Windows partition to take up all the
free space. That should do it for you. An alternate would be to reformat
the extended partition as NTFS and this should provide you with a
partition that Windows can use (probably becomes your D: drive).

That sounds like a good plan. I appreciate the detailed
instructions beyond "use gparted" which is what I expected. Good job.

I've copied and pasted and will give it a go in the next couple of days when I
get some time.

I'm also going to continue to try to install Lubuntu 12.04 on the old laptop.
That distro looks like the way I'd like to go with my main machine, now running
Ubuntu 9.10.

I have tried that on more than one occasion. If you have the windows
disk the below directions work after you insert the windows disk and
select repair installation. The problem is the MBR (master boot record)
that was altered when lubuntu was installed.

It all depends on if grub (the boot loader) was installed by the lubuntu
disk/flashdrive.

I would just change the size on the Lubuntu install to a absolute
minimum and loose the 4gig to Linux unless I had an XP disk.

I don't have any of the Windows disks. This was a Graigs List machine.
Came with a desk but no software. :)

The problem is that Lubuntu never did install. There's no Grub that I know of.
The machine just boots to windows. When I use the Live CD I can see that there
are two partitions, one for Windows and the other ready for the Lubuntu OS. IF
Lubuntu had installed I would just keep and use it. Since it didn't, I just want
to get back that 40 gigs or so that are sitting there not acessable by Windows.

I have some time today and will try the gparted suggestions below. My concern is
that it might screw up Windows but it's worth a shot. If all else fails, I'll
end up with another Linux box and continue my search for a cheap Windows
machine. :)

You can back up your complete Windows partition with a freebie called
Clonezilla. It can be booted from a disk or from a thumb drive.

I've used it before I reorganize partitions with GParted.

Did the gParted thing yesterday and it worked out just great! Very easy to do.
Actually "deleted" the listed partitions and "expanded" the Windows partition
before finding the "make it so" button. CLicked that and it did all the right
stuff in the correct order. Got the whole drive back for Windows which will
allow for some video editing stuff. Thanks for the well written help on this
one.

You're welcome. Us Linux folk have to stick together and help out those
who are new to it. I have had a lot of help from these folks along the way.