Need help with DirectX

Hey guys. I' new here and I would like your help with a problem I've been experiencing. My laptop has an intel core i5-2450M, 2.5GHz processor. I have an nvidia GEFORCE GT 630M graphics card, 2gb. My laptop can run most new games smoothly on mid-high settings. But recently, I bought a PC classic, the first Crysis. And I have been having some frame-rate and lag issues. I have been told that it runs better on dx 9 than dx 11. How do I downgrade my dx from 11 to 9? How do I select which direct x to run the game on?

Any help will be greatly appreciated.
Thank you.

What he said, but it won't help you much.

crysis might be old, but it's pretty rough to run, since it looks better than alot of modern games.
DX11 should not run slower than DX9, it is an improvement over the previous versions, and handles the same task quicker.

The only reason a DX9 setting would help you here is if it locks up certain SFX's, in which case, you could do better by just cranking down the settings by yourself, while keeping it DX11

Not sure crysis one can utilize dx11 though, since the newest thing out by that time was 10.

I tried that but it didn't make much of a difference. But I was able to go to my games library, right-click on the icon and select dx 9. Thanks for your help anyway, Sir.

You don't downgrade dx versions, the API is built into the operating system. It does however carry support for the previous API's.

DX10 in crysis basically comes down to the Shader Model being used under ultra settings (SM4.0 instead of SM3.0), turning you settings down to high from ultra will net you more or less the same results.

The 630M just really have a whole lot of grunt to it i'm afraid.

The DX9 in windows 7 and 8 is fake. its emulated the emulation runs faster it also dont have things. DX9 support don't have the the cool shaders.

So you can not downgrade there is an emulator tool for dx9 already on windows 7 and 8. real DX9 support stopped at windows xp. You have to install it if it is not on the system it runs in another way from the main dx10 or sx11 so they both have to be on the system.

dx11 is the main system and dx9.0c that you install will only be used by a emulated support when it needs dx9 support.

All dx10 and dx11 just overwrites and updates the real DX supported by windows 7 etc the dx9.0c is a whole other thing in windows 7.

I am starting to see that. I was however able to run Far Cry 3, Tomb Raider etc on mid-high settings. Arkham Asylum and City on very high. I don't know why Crysis is giving me problems. It runs well on dx 9 on high but with a few frame-rate drop here and there.