bootcamp
The choice of which portion of the hard disk (apple or windows) no longer appears and I only can boot to windows
Windows, Windows 10
Question marked as
Can you see it if you restart holding down option/alt (one needs to connect a bluetooth keyboard by wire)? If so, select Macintosh HD and go to the Startup Disk preferences to make sure it is selected. I find this tends to happen after Windows updates. If you don't see Macintosh HD when you do this, try restarting holding command+R to go to Recovery. You may be able to repair or restore the Mac partition from there.