There are other threads related to this question for Ubuntu 12.04, however THEY DO NOT APPLY TO 12.10. This is not a duplicate of another thread if the referenced thread doesn't answer the question asked.
Ubuntu – How to install the latest ATI Catalyst Video Drivers in Ubuntu 12.10 Quantal
For the purpose of this question: Catalyst = fglrx = proprietary AMD/ATI display driver
The most problems people are having come from the fact that:
1. Ubuntu has moved to newer driver versions, that don't support some older ATI/AMD chips
2. Ubuntu has moved to newer Xorg versions
No. 1 - 'not supported' errors / Jockey not detecting proprietary drivers valid for installation
No. 2 - some older ATI/AMD Catalyst versions won't install
Which all comes down to:
Your chip is no longer supported by the latest ATI/AMD catalyst display drivers (be it via manual install or from Ubuntu repositories)
Check, what is the latest driver version that supports your chip and then proceed with the installation accordingly.
http://wiki.cchtml.com/index.php/Hardware (may be slightly outdated)
enter your graphic card details here:
use terminal command to display information about your graphics
If the latest version for you is 12.6 => proceed as per https://askubuntu.com/a/201785/29347
Chips that are indicated 'legacy' (not supported for the latest Catalyst versions):
Try the PPA listed here How to install old AMD Catalyst 12.4 drivers on Ubuntu 12.10? You'll most probably get Catalyst 12.6
Chips that ARE supported in 12.10 / by the latest Catalyst drivers:
The installation should be accomplished as per What is the correct way to install proprietary ATI Catalyst Video Drivers (fglrx) directly from AMD?