I see a lot of people on Win7 64 having Riven crash on start-up. (I have an nvidia 750ti).
All I get is a black screen.

Now if these people had two more data files (b_Data1.mhk and j_Data3.mhk) they could play it through Scummvm without any problems.

The GOG version does not include these two files and they are not available anywhere else.
I am just posting this so people will know that there is a simple solution which has not been accommodated.

You have to get a development build, not the stable build of scummvm.
It plays fine with all the videos working so far.

Scummvm was the only way I was able to get this game to work on WIn 7 64. So GOG should probably provide this game with Scumm, as it does with other games.