|Main GUI... (use it at your own risk)|
But with Windows XP, the OS is so old that even if you have a CPU which was introduced around 2005-2007... with XP, setting advanced options, most of the time are not possible. In that case if you're looking for a fully featured ACPI manager that lets you control not just CPU but other things like...
*. CPU speed/Voltage settings.
*. Hard drive speed settings (which can help to get a noticeable amount of battery life).
*. Various battery related options/settings and readings (how many percentage it has, etc).
*. ATI GPU (VGA cards) related speed settings that can enhance battery life.
*. CPU/HDD temperature monitoring.
*. Easy to use GUI +, you can set it to display live data about your PC on the desktop as well.
These are among the main features of NHC - Notebook hardware control.
Unfortunately this is only for Microsoft windows users... cannot be run in GNU/Linux. Even if you have Windows Vista or 7 still I think this is a more powerful tool than what those OS allow their users to change (safely). It comes with main two versions, free and a professional one.
Before downloading, I advice you to read this FAQ first and then proceed to this downloading page.