I've got it on my dell laptop and it allows me to tune my cpu/battery to how I want the settings. If I want max. performance and to hell with the batteries, my choice.

As you can see ( if you look at it), you can REALLY refine your settings.  But be careful... it can bite.

Nice thing also... it's light on the resources and doesn't mess up your native settings.

http://www.diefer.de/speedswitchxp/index.html 

try it.

Ron