Are we talking sharing via wireless? If so, I don't have an answer 'cause I had the same problem with my Win7Pro & Win8 [until I went all Win7Pro]. If talking hardwire, was easier than wireless. Can you presently share portions of your data partition amongst the two computers?
For future printing ease, I think you may have to temporarily attach the printer to the 2nd computer, get the drivers up to speed. Try sharing again. Can printer be attached to either computer? It's possible that one OS will do better sharing printer than the other OS.