If there is a driver missing, you should see a yellow exclamation point in the Device Manager. Right click on My Computer ansd select manage and the Device Manager. If you ar missing a driver it will show up as yellow exclamation or question mark. Go to CAMusing's link, the firs thing that comes up is:
BIOS update for Satellite A100/A105, Satellite M110/M115, and Tecra A7
Have you appled that? You should see BIOS version on boot.
The driver available for the ATI is for Vista, which may work, or that may possibly be the problem. It says this when I click on the download on page 2:
Version: 83110032
Size: 87,420,584 bytes
Posted: 01/25/07
Released Date: 01/25/07
Applicable Categories: Display, Driver
Operating System: Windows Vista
Package: WinZIP self-installing ZIP file. Can also be unZIPped using WinZip, PKUnZip or equivalent. Also supports silent installation. Click for silent/unattended installation instructions.