Graphic card installation problem

[Halil Kaya]

Hi. I've just bought a new notebook. It has an external graphic card: AMD
Radeon HD 7670M 2GB. I installed Ubuntu 12.10. I've been trying to install
the driver for more than 2 hours. However, I couldn't do it yet. When I try
to install the drivers that Ubuntu indicates, I reboot my PC, an error
occurs: You are using low-graphics... (like that). I also downloaded the
driver from AMD web site. I faced this situation again. Please help me
about what I should do. Thanks in advance...