how to convert protected files to MP3 format
How can I convert protected music from my ITunes library to unprotected so that I don't have to purchase them again
null-OTHER, Windows 10
NOTE: this is only music, video & other media are different.
It depends why it is protected.
If the files are protected because they are part of the Apple Music subscription service you cannot do anything with them.
Apple fairplay DRM (the original iTunes store DRM) allows you to burn iTunes store purchased files to a CD. Create an 'audio' format CD & then rip that inside iTunes & your files have no DRM. Apple allowed that as part of the FairPlay features.
Another option is to use iTunes Match (a paid subscription) - the idea is that DRM'd files are matched to Apples online store catalog in iTunes. If the store has non-DRM versions you can download those & replace you protected files.
If the files are from another store you need to consult the help on that store.
Otherwise you can consider purchasing the files from the iTunes store, they don't have DRM these days.