The IDirectInputDevice2::GetEffectInfo method can be used to retrieve information about the device's support for an effect. It retrieves the same information that is returned in the DIEFFECTINFO structure during enumeration. For more information, see Effect Enumeration.
The following C++ example fetches information about an enumerated effect whose GUID is stored in the EffectGuid variable:
DIEFFECTINFO diEffectInfo;
diEffectInfo.dwSize = sizeof(DIEFFECTINFO);
lpdid2->GetEffectInfo(&diEffectInfo, EffectGuid);