System crash after "zoom" installed

Have you already tried simply to remove and purge compiz...

sudo apt-get purge compiz

Hope this helps

Yes i did, and it does not resolve the problem. I'm still stuck in circle at login screen.
Is there any other way of getting this resolved (short of reinstalling the whole system)?
Thanks a million.

Please try first to restart your graphic layer press when you see login ctrl+alt+F2
Then if this doesn't solve...
Press ctrl+alt+f2 and make login with your user and password... then type:

sudo apt-get update
sudo apt-get upgrade

sudo dpkg-reconfigure -phigh xserver-xorg

sudo reboot

Hope this helps

Unfortunately this did not help either.
Do you have anything else for me to try?
I really appreciate your prompt responses and determination to help me fix this problem.
Thank you.

What you see when you try to login only a circle or the login prompt...?

Thank you

Please try...

sudo dpkg-reconfigure gdm

My boot process is ok. Grub works fine. My login screen is where I have a problem. This screen itself functions fine and it looks as it always looked, but I can not get past it. It will let me enter my user and password and then it attempts to bring my desktop up but it fails and it reverts back to login screen.
Now let me go back and try this last command line you suggested (I'm floating between ubuntu and ms windows here).
I'll get back in a minute or two.

Press ctrl+alt+f2 and make login with your user and password... then type:

sudo apt-get --reinstall install ubuntu-desktop

sudo reboot

Hope this helps

No, nothing happened...
One thing I noticed while running 'sudo apt-get --reinstall install ubuntu-desktop': several lines flew by saying something like: "unable to fetch http://....."
Could this be part of the problem with making these changes - I do not have my internet connection established until I am fully logged in?

You can try to add a new user and try to login with it:

Press ctrl+alt+f2 and make login with your user and password... then type:

sudo adduser new

give a user password

then try to log with the user "new"

Hope this helps

OK, marcobra, this is working. I am in as another user. Nice job. Thank you very much.
Now, how do I go back to my original user and/or retrieve all my settings and data?

Please close this question and open new one about this... this a very different question from original... and you will get better answer if you made a new fresh question about this... and i must go bed now... in Italy is very late...

Thank you

No problem, I will do that.
Mille grazie e buona note.

di niente ;-) ciao Miro