Can't install Ubuntu since 10.10

Solution 1:

When you boot from the live CD press and hold down the left Shift key. This will, after having selected the language, enter the Grub menu:

Press F6 at his screen and select "nomodeset" as a boot option to prevent loading of video drivers during boot.

If that does not resolve the issue try with the alternate CD for a text based installation.

In case you will not be able to boot into a graphical desktop you may try to install the Nvidia graphic drivers from a terminal, e.g. with jockey-text.

Additional note from comment: after a successful installation we may be able to boot to "Recovery Mode" (again hold left Shift key for Grub menu) to install graphic drivers, or if that fails drop to a shell to proceed driver installation from command line.