That is the problem. And for the record am not 100% certain I am correct on how it works as I don't own one.
I think the BIOS is where you change the multipliers. If a model had versions that supported then you just flash the BIOS if not already supported. If your model never supported you would be mostly out of luck taking advantage of unlocked multipliers. There are people who Mod BIOS but that gets involved finding if one even exists. If you are going to spend the cash on X series CPU's I recommend making sure your model or very similar with a BIOS that would work offered the X CPU. If not just get the highest clocked locked and OC FSB. Yes they do physically fit but if you can't use the OC feature sort of a waste of money.
My old desktop was able to up the Mhz multiplier in the bios, but my other laptop, dell XPS is pinmodded. which gives it the new multiplier by which to run the FSB. What is the best way to overclock this 8800m Gts card by the way?