It has been stated before that disabling the ATI hotkey poller will cause you to lose the powerplay function of the x1600. That means that your card will not underclock when on battery and this will cause a decrease in battery life.
mobile catalyst. Search the forum for the link. It has been posted countless times.
As to how I installed:
1. Uninstall previous Drivers, CCC, ATI Software Uninstal Utility
2. Run Driver Cleaner
3. Run Driver Cleaner in Safe mode (optional)
4. Run the executable that you have downloaded.