This is how to fix the annoying automatic 60Hz to 40hz refresh rate switch when one goes from AC to Batt. (you will notice the screen go blank temporarily as it switches). To see what I'm referring to, simply right click your desktop, choose Graphics properties and make sure you are using the advanced layout. There you will see the current refresh rate. Open regedit (type regedit in start menu search box) Navigate to: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Classes Now hit Ctrl+F or select find from the edit menu. Search for: FeatureTestControl When you find it, change whatever it currently is to f840 (as hex) or 63808(decimal). Reboot. Now it will stay on 60Hz whether you run on A/C or Batts.