What information does Windows Media Player exchange or store during sync?

Contains information stored about all devices that the Player syncs with. The Player also stores information about the files in your library that have been synchronized to each device. Storing the information reduces the time required for the Player to recognize a device and the files to sync to it when you connect the device to your computer. For some devices, the Player also places a file named WMPInfo.xml on the device to track the sync partnership.

Specifies information the Player determined about the capabilities of the device you are using to sync with your computer, such as the file formats and bit rates the device can play, the amount of available storage space on the device, and whether the device supports storing files in folders. The Player will not try to sync file types that your device cannot play. For mass storage class devices, the Player can only determine the available storage space on the device and only sync music files to the device by default. To sync other file types to mass storage class devices, drag the other file types onto the device; the Player cannot automatically sync them. (You can tell a device is a mass storage class device if your computer assigns a drive letter to the device when you connect it to your computer.)

Specifies the types of media information the Player can sync for music files, if the device can display the information: album art, track artist, track title, album title, album artists, track number, genre, and release year. If your device permits you to mark an album for purchase later (for example, by selecting a Buy CD command), the next time you connect your device to your computer, your Internet browser will open a webpage that allows you to complete the transaction.

Specifies what you can do with a protected media file if you sync it to your device. The media usage rights for the file are also synchronized to the device. Media usage rights may contain information such as the number of times you can play the file or an expiration date. Typically, any files that you obtain from an online store are protected with media usage rights. For more information about protected files, see DRM: frequently asked questions.

Specifies the number of times a file was played, both in the Player and on the device. The play count is updated in your library and on your device during sync. If the file is protected with media usage rights that specify a limit to the number of times the file can be played, the updated play count is used to determine if the limit has been reached. In addition, auto playlists in your library that have criteria based upon play count are updated with the play count, and auto-ratings, which change based upon the number of times an item is played, are also updated.

Identifies the time a file was last played on the device, so that the auto playlists in your library that have criteria based upon the time when files are played are updated appropriately.

Updates ratings information for files in your library if you changed the rating for the file on the device. Your device must support the ability to change ratings. The auto playlists in your library that have criteria based upon ratings are updated appropriately.