Since it won't open, you gotta do it the other way. With the files. But it should be easy. So:
1: Open the FeralHeart folder
2: Open a file called "ogre" in notepad (it's a cfg file)
3: Erase what's in there
4: Put this in:
Render System=OpenGL Rendering Subsystem
[OpenGL Rendering Subsystem]
Colour Depth=32
Display Frequency=N/A
FSAA=0
Full Screen=No
RTT Preferred Mode=FBO
VSync=No
Video Mode=800 x 600
sRGB Gamma Conversion=No
[Direct3D9 Rendering Subsystem]
Allow NVPerfHUD=No
Anti aliasing=None
Floating-point mode=Fastest
Full Screen=No
VSync=No
Video Mode=800 x 600 @ 32-bit colour
sRGB Gamma Conversion=No
5: Save it
6: Start up FH and see if it worked.
Hope this helps. (You both.) ^^