I installed beta 9 some time ago. Now the default location for the sketchbook is stuck. I just installed RC3 and it creates the old beta.9 directory and defaults the sketchbook location to: ~\Documents\arduino-ide_2.0.0-beta.9_Windows_64bit\portable\sketchbook.
I browse and point it to the new location, but after clicking OK, it does not stick. It reverts back to the previous location.
Is there a way to clear this and reset it back to the default so when I browse to the new sketchbook folder location it will look there?