PII 266 Bios Msg.

On boot up the bios reports: Pentium II MMX CPU at 133MHz , Host bus 66Mhz. I would like it to find a PII 266. In the bios, chipset feaures setup, the CPU Host/PCI Frequency is 66/33 changing this can get a msg of 166MHz. The computer is stable and works ok. The M/B is a microstar model 6147. Any ideas much appreciated.