pc2700 running as pc2100

i got this pc2700 and put it in my rig and its running 133mhz instead of 166mhz

Well if it is the mobo in your sig that you have the PC2700 memory installed in, that is why it is running at PC2100 speeds, you said it all, cant OC. In order for PC2700 memory to be able to run at its potential it needs to be set to 166fsb and if your mobo wont allow for an OC and it is a 133fsb board you wont see the benefits of having PC2700 memory.

the mobo is a 200fsb board , 2.4c running at 2400 mhz...

Is there any FSB or divider options in the bios?