You can get ATITool 1.24 from the files section. Make sure you get the newest drivers from ATI, the 5.8's. If you have any problems with those just switch back to the 5.7's from the files section. When installing new drivers make sure you first remove any and all display drivers from the control panel. Then download Driver Cleaner Pro from
here. Boot into safe mode (tap F8 to enter the boot menu) and run driver cleaner pro and remove all display drivers, nVidia included if you had any. Boot into Windows and install the new drivers. This should give you the best speed/performance and prevent any driver conflicts. Enjoy!