Playback of purchased music (DRM) does not work

First make sure you have the latest software on your PC and in the SLM5500. 1. You can upgrade the SLM5500 with the latest software by registration for the internet services (see settings menu), after registration you can check in settings menu if a new software version is available and you can select to upgrade 2. Choose the latest Philips Media Manager software to ensure you can playback protect music files (You can upgrade to the latest Philips Media Manager software by checking via the menu on the PC if a new version is available via the internet) 3. Check with Windows Media Player if the file can be played only this type of DRM software is supported