I've done some Cakewalk upgrades (6 thru 9) and generally I've found that the newer version tended to be installed to a different directory than the older one. To update configuration, sys-ex strings etc I just copied the required files into the relevent new program directory. The instrument definiton file format was unchanged.

The biggest area of difficulty was updating projects containing audio (due to the new audio file location differing from the old one), and as a result I now have a dedicated "Cakewalk Audio Scratch File" directory which is somewhere different to Cakewalk, so that I just tell the later version of cakewalk to use the "my" audio scratch file location.

As I think Sonar is a "well behaved" application, then I would personally not remove the old version prior to installation in the hope that the new version will pick up the old version settings. I can't remember this happening with the older versions, however.

YOur "new" Cakewalk should "see" all installed Midi devices and should not corrupt their installations. You should not have to reinstall any drivers.

I'd copy the "Old" cakewalk somewhere safe first just in case!

Hope this helps!