I forgot to mention that when I log in with Ubuntu (after it has been installed)
I am told of a problem with the system and it drops me to a console window but I
don't know what to do. Before I installed Ubuntu I deleted the .kde directory
as I know the system would create a new one if it wasn't there when I logged in.

I don't want to format the home partition as I have some files on there I have
not yet backed up (my external hard drive died last night).

I'd try something a little more extreme, but still not as extreme as
starting totally over.

I'd create a new account from the console (I think you said you could
get to the console) (the useradd command), then see if I could log in
as that user. If I could, I'd make that user an admin (add it to the
admin group in /etc/group), then use it to fix the problems with your
original account.

To do that, I'd remove all the dotfiles and directories to a
subdirectory (I call it olddots when I do this), then I'd copy over
what I considered the important dotfiles from the new account, and see
if that fixes the problem. I'm about to leave for lunch and people are
waiting, so I don't have time to look up which ones look essential,
and whether eny will need to be edited for another user's home.

If you can't log in from the newly made account, let us know, and
maybe someone can help.

I'm still fairly new to ubuntu.

M$ Windows has a safe mode where when you start in safe mode you can fix
problems such as this. Doesn't ubuntu have something like this?

Try formatting EVERYTHING, including the Home folder. Then, reinstall the OS.

sounds like the os on your disk might be corrupt without knowing what you
did with your setting al i can tell you is to wipe the drive and start over

I enabled the "Desktop effects" from the "Look and feel" section of "System
settings" so I could play with the 3D screen system I have seem elsewhere.

I don't want to format the entire drive unless I can back-up things like my
browser bookmarks and files I have not yet backed-up elsewhere.

What about creating a flash drive boot drive to load the system and
using a second one to copy the files to?

Start your system using the CD, This allows you to work on your system
and back up anything you may need to. Not knowing what you did it
makes it hard for anyone to help without studying your puter first
hand. Because you have allready started with a re-install you may as
well continue, or at least that is how I look at it, no telling what
files have been damaged.

A recap:
1. use the CD to start the system.
2. Backup your saved directories to CD or removable media.
3.Make a fresh install, but before you do make sure all the settings
you have made to make your system special to you are saved if you can
find them.

Like others say this is extreme, but then you have already taken some
of these steps before you asked.

Thanks to everyone who offered help. I managed to sort it by deleting some
files with . at the start. Because I deleted several files in batches I suspect
it was the hidden session files that was causing the grief so when I got rid of
those the problem went away as well