12.10 installation deleted most services and all customization and now doesn't boot

[jcobban]

I did the following:

1. downloaded and burned DVD of 12.10
2. I was not in a hurry to install 12.10, I just wanted it handy, and to have to give to a friend who is trying out various distros. But at some point Update Manager started insisting that a 12.10 DVD be mounted on the system, and refused to apply any changes until I did so. The reason I was trying to apply changes was because until you have applied all outstanding updates you don't get the prompt to perform an upgrade to 12.10 on a running system. However even though Update Manager was demanding that I mount a 12.10 DVD it did not accept the one I had burned in step 1!
3. Although it was not my first choice it appeared that the only way I could get past Update Manager's insistence on some specific version of a 12.10 disk being mounted was to perform the upgrade to 12.10 using the DVD rather than over the net.
4. While doing the upgrade using the DVD a message popped up that the installer was unable to restore some services.
5. Sure enough when I booted into the upgraded system almost everything I had installed on top of the base system was gone.
6. I spent most of yesterday trying to remember everything I had installed and manually reinstalling and reconfiguring it. This included GVIM, Eclipse, Apache, PHP, PHP-MySQL, PEAR, several PEAR features, etc. etc.
7. Finally I got the system to a working state, but by that time I had thrown away the entire day. So I closed the lid of my laptop and went to bed.
8. In the morning I opened the laptop to face a black screen. I couldn't think of anything to do but cycle power.
9. I am now looking at a blank PURPLE screen. The system is up: I can ping it. However among the services that the install threw away was the telnet and ftp servers so I cannot even get into the system through the back door.

So the system is broken, but where do I go from here? In particular as a first step how do I get to a terminal when the GUI is dead?

[jcobban]

I have got past the booting problem by:

Alt-PrntScr-R-E-I-S-U-B

I selected the Ubuntu Recover option from the list of boot options and did an FSCK. Trying to continue the reboot did not work, as warned, because the driver for the AT style graphics was not available. So I repeated the keyboard reboot as above and this time was able to get into the GUI. Almost immediately the dialog about a GUI software failure popped up, and I selected the option to report the problem. Then the GUI software failure dialog popped up again, and I again reported the problem.

The system is still obviously unhealthy, so I still need help to get it working reliably while I continue to restore all of the stuff that the 12.10 install threw away. For the moment I am applying the 206 updates to get the 12.10 system up to date.