For those of you who are reinstalling the OS from scratch and want to avoid loading all of the Sony software (including PowerProfile), you may want to check out this program.
http://www.diefer.de/speedswitchxp/
Basically, it works with Windows XP’s built-in power management to allow you to define the power profiles and control the CPU speed. It’s basically a lot like Intel’s Speedstep for Win9x and Win2k OSes.
You have the option for Max Performance, Max Battery, Dynamic Switching, Battery Optimized.
The only thing it doesn’t do is control screen brightness and powering on/off the MS slot and optical drive. However, if you don’t care about those you can use this software.