No need to uninstall any version. On tne contrary, you could find that there are effects, collages, intro/outros, audio files, etc in MEP 17 that have been dropped in MEP 2014. If the former is still installed you may (with care) be able to copy them across to the corresponding folders in the latter.
I currently still have MEP 14, 15, 16, 17, MX, 2013 (my current preference) and 2014 installed. MEP 11 and 12 were finally zapped a while ago!