Try manually installing DirectX yourself. I'll put a link below, or, you can manually change it via the ogre.cfg file. Simply open it in notepad and the first two lines can be changed.
DirectX (http://www.microsoft.com/en-us/download/details.aspx?id=35)
Rendering System Tutorial (http://www.feral-heart.com/index.php?option=com_jfusion&Itemid=2&jfile=index.php&topic=43234.0)
~ Whisper
Or maybe check through your particle folder, make sure there are no duplicate files. Files ending in _0, _1, _2 and so on.
Try running Feralheart on different rendering systems to see if that works, or as Alpha said, try installing DirectX manually. If none of these things work then I'm afraid you'll have to contact a moderator for help. Best of luck to you!
Ah, thank you all so much! The problem was the particles; after I cleaned them out the game worked perfectly. Now to re-install the maps and such. -sigh- Thanks again!
Good to see the problem has been solved.
You're welcome ;)