Remove all ATI drivers @ Control Panel>add and remove programs.
You could use something like NFR also after driver removal. Heres a link: http://majorgeeks.com/download3233.html
This will remove ATI and nvidia drivers.
Install an earlier "Driver only".
See if this helps your sitituation.
I looked at Asustek.
According to what is writen the latest chipset driver does not support Vista 64. Could be an error or you might have to use a diffrent chipset driver. Was the chipset driver you installed, did it say it was for Vista 64?
Have you gone to their web site. If you do you will see what I mean.
On the other hand you might not have openend windows at all if you had the wrong chip set driver.