Should be a setting in the BIOS to set it to performance or max. Did you update your BIOS to the latest one. I have a DELL with this feature, and the CPU PIII runs at 1.0 GHz or 700MHz with speed step turned on. I had mentioned the power control because you can tell the PC to always be on that will kick up the CPU speed back to what it was.
Which CPU do you have in that?
I also have AMD Mobile they have a feature that runs in Windows XP Pro that you can control the core speed of the CPU. Based on the battery. So I am running on that laptop at 1.8 - 1.9GHz all the time. Or if I want to save the 12 cell battery I can run at 800-900MHz.