Those are the key. Now that key is tied to that OEM and that motherboard, if you are trying to install it on a different computer it will not work.
If it is the same computer then look for typos. Microsoft has made the font smaller, and chose one that is hard to tell the difference between B and 8, 0 and O, I and 1 etc etc, and that black ink on blue background for some stickers is another brilliant addition. Top Notch Microsoft, Top Notch. (Ok I will quit ranting now).