Have you gone into CMOS Setup to see whether your BIOS allows setting the CPU speed? On my system, I can set that at 100 MHz or 133. It seems quite obvious that your system is showing a processor speed of 1.33 GHz because the CPU speed is set at 133 MHz in the CMOS settings. If you go into CMOS Setup and set that at 100 MHz, you're processor will run at it's rated speed.
Edit: BTW, why don't you delete your other/duplicate post? You posted this twice.