To copy your settings and custom thematics, symbols etc from a older version to t new version navigate to –

 C:\Users\USERNAME\AppData\Roaming\MapInfo\MapInfo\Professional\1500\

And copy all of these files to the newest version folder –

 C:\Users\YOURUSERNAME\AppData\Roaming\MapInfo\MapInfo\Professional\1900\

Where 1500 is the old version, e.g. 15.0, and 1900 is the new version, e.g. 19.0

Normally this is all that is required, however with MapInfo 17.0  they changed the structure of this folder and you need to run a special tool, see the MapInfo KB here -

https://support.pitneybowes.com/SearchArticles/VFP06_KnowledgeWithSidebarTroubleshoot?id=kA280000000PFj5CAG&popup=false&lang=en_US