One problem I just had with my laptop is that when iTunes ran, it had changed all the paths to my music library to some strange "localhost/e:..." path so the entire library was unlinked, so I lost all my playlists, song ratings, etc. I think MS did it on purpose because just to get something playing I clicked directly on a music file and of course that took me to the MS player which of course defaulted to a screen that offered easy setup for their music services and stores.
I'm sure I could have come up with a utility to find/replace all the bad file paths with the correct path since Microsoft didn't change the default location of the music library, but I was in a hurry. One thing I did find out that is totally stupid is that apple has removed the option to add an entire folder to the music library. You get to add files one at a time, or put them in your library and then click a fairly scary "SCAN FOR MEDIA" button, which may or may not search outside the folder set as the location for the media library.
So, complete fails for both apple iTunes and the windows 10 upgrade in this regard. ITunes lost some critical functionality and for some bizzare reason changed the music file location for my music library to a drive that doesn't even exist, and something in the windows 10 upgrade process triggered this idiotic behavior of iTunes. And of course Apple had to remove the ability to add random individual but complete folders to the library, forcing instead you to place any music inside a specific media library and then making you push a button to re-search and re-index the whole damn library just to add one new album.
