This really sounds like a codec compatibility issue. Some people have BR playback working over all version of windows 7, therefore there software such as the one bundled with the LG player will have the compatible codecs that when installing the program integrate with windows 7 as well. This is vital, as with any versions of windows and media player if you do not have the codecs required to playback the video content whether it is xvid, wmv, mkv, .h264 then it will crash and error out.
J