I upgraded from win7 to win10 and because many of my ancient programs stopped working, reverted to win7. Before this, however, I had upgraded Calibre and so had to unistall it and install the 3.48 version. While editing a book, changes were slow to update and saving the file took a great deal of time. I exited the editor and calibre and restarted calibre. The editor would not open. I have since done an uninstall, reboot, install and even tried older versions, but am still unable to get the editor to work.
I am guessing there is something that is not erased in the uninstall that persists, but what?
