Ahhh - that's interesting as honestly didnt even think of that - Not had problems with Direct x for a very long time always seem to be a driver issue............
So guessing something changed or corrupted the MS direct x :9
Glad you got it sorted and thanks for posting back as we and all can add this as a possible fix to other fantastic issue we may encounter with our loved MS
Ahh yeh me on windows 7 and on DX11 also - you can go to start Run and key in "dxdiag" to see settings and stuff but surprised it downgraded but yeh when ever a game asks you to install Direct x dont as normally you will have the latest or above and so far Direct x is fully backwards compatible and all most all drivers are also fully backwards compatible but we are seeing new chipset's mainly Intel on lap tops and onboard graphics that are dropping support for features that were used in old games........
Now you got it working dont forget to get yourself a roll back backup for Windows has bailed me out loads of times