Is t probably that i've DiretcX 11, and my pc doesn't support a game older than directx 11? Because now i just check this and only with Ragnarok happened this. Only with RO (I've dead space 3, the last tomb raider, Need for speed Hot pursuit the latest version, NBA 2k13 and none of them is giving me error). What can I do in order to avoid downgrading my directx from 11 to 8?
No, DirectX is backwards-compatible with previous versions.
Try reinstalling the Visual C++ 2008 run-time library.