Yes, the 800 MHz clock speed will not help, for sure...
Anyone played with/tinkered in the BIOS settings or power plan recently?
First, what is your system? any idea of cpu/mainboard? (Then can investigate possible BIOS settings to look for)
Second, within WIndows, go to control Panel/Power Options, and make sure "Balanced" is selected, and NOT 'Power Saver"