ASUS NVIDIA 670 GTX WEI Readings

My new 670 GTX, scores a 7.9 in Windows Experience Index and when i clicked print info and shows the details, everything looks good, but im just wondering why it shows that its running DirectX 10, my older 450 gts does the same and so does my friends Radeon HD 6770. Is this just a WEI issue or what? im not concerned just wondering as its only WEI lol.