Bios show my ddr2 only 667?

I build a new pc and bought Kingston hyperx ddr2 800Mhz but bios shows it working as 667Mhz. I have read some posts about memory overclocking and i'm not sure how to raise it so can you tell me in detail how i can get it to 800Mhz?

By the way is 40c-42c too high for idle temperature for E6400?

Not to familiar with hyper-x... but what are the timings advertised on the package for the CL (Cas Latency), what size are the modules, and do they come in a kit (as a pair) or did you buy a single one?

Is it possible that the 667MHz is what's on the SPD, to make it easier to boot for the first time with the RAM? Sometimes there is trouble because some DDR2-800 cannot run at the default 1.8V, meaning there is no way to get to the bios to change settings.

In this case, all you need to do is get into the BIOS, find the sections with RAM ratios/multipliers/voltages, and change a few values to whatever it's supposed to be.

I just saw your link:

This pretty much confirms what I thought. The RAM is programmed to default to these settings. You just have to change it in the BIOS.

Did you read the fine print at the bottom?
Did you read the normal print at the top?

He just needs to go into the BIOS and change the RAM voltage to 2.0V, and change the multiplier to 3 (or the ratio to 3:2), and the timings to 4-4-4-12. (I am assuming a Core2 at 266MHz FSB)

It's normal to have to make adjustments to run 800MHz DDR2 at the advertised settings (unless your RAM and motherboard both have EPP, then it should do it itself).

Thanks for the info especially Mondomans post helped me understand how it works.