Why won't my .mp4 files play on Windows 10 after installing Apple music?

.m4p tracks are protected. These could be pre-2010 DRM protected purchases, or content downloaded from the Apple Music service. Do you have a subscription service? My experience is that media from the Apple Music service won't import into a different library and must be download fresh. Audio tracks purchased from the iTunes Store post-2009 should be in .m4a format, not m4p.

FWIW if you remove the Apple Music, Apple TV and Apple Devices apps you'll be able to access your music in iTunes again.

tt2

The pre-2010 tracks would have originally been subject to a one successful download policy, and would only play in iTunes authorized to your Apple ID. They may not necessarily show in your account's purchase history. Apple once provided a scheme to update .m4p tracks for a small additional fee to what was then called iTunes Plus, and it is potentially possible to update them in iTunes with a subscription to iTunes Match, provided the same songs are still in Apple's catalog. It should also be possible, with iTunes, to burn them to audio CD, then rip back to the computer, although that will result in a small loss of quality.

Apple Music for Windows seems to be missing many features from iTunes. It would seem support for legacy DRM protected music is yet another one.

tt2

You're welcome. 🙂

tt2