Empty files on Samsung MP3 player.

MP3 players can only play music files in mp3 file format.You need to convert your CDs to mp3 music files onto your computer ordownload them from the Internet and then copy them to your MP3 player.
You can do this using Windows Media player and Rip the CDs - Media Player willcreate a MP3 music file for each music track.
Click on this link for instruction on converting music files to mp3 file format:-
http://www.fixya.com/support/r5798418-creating_transferring_mp3_music_files

Don't download music illegally and you should be fine.

LOST CD CANNOT SYNC FROM MEDIA PLAYER MUSIC CAN IT BE DOWNLOADED

limewire is your best bet when downloading music, and when u transfer it all u have to do is open your MP3 player in my computer to where the files get saved then drag the desired songs from limewire the the file where they are saved

• The USB mode uses a file transfer class called the MSC (Mass Storage Class). This was developed as a way for files to be transferred onto an external drive such as a flash drive or an external hard drive.
• In this mode, your mp3 player will look and function like an external hard drive in that it will appear in My Computer as a separate drive. This transfer class is not very specific to the transfer of media files so the MTP (Media Transfer Protocol) was introduced.
• The difference with media files, specifically music files, is that they demand much more management.
• Downloading services can require special licensing and a limit on the number of playbacks a music file can have.
• The acquisition, restoration, updating, and backing up of these licenses as well as compatibility issues with file type and compression ratio within these digital music players demanded a more user-friendly and functional approach to file transfers.
• For this reason, you will need to have Windows Media Player 10 or 11 available on your computer to utilize MTP.
• Those with Windows Media Player 9 on their Windows 98 SE, Windows Millennium Edition, and Windows 2000 operating system will need to update using our Download Center.
• We recommend the use of MTP over MSC (the USB mode on your player) because it is more specific to the transfer of music files. To change this setting, press the power button on your device once it’s connected to the computer until the USB icon disappears.

• The USB mode uses a file transfer class called the MSC (Mass Storage Class). This was developed as a way for files to be transferred onto an external drive such as a flash drive or an external hard drive.
• In this mode, your mp3 player will look and function like an external hard drive in that it will appear in My Computer as a separate drive. This transfer class is not very specific to the transfer of media files so the MTP (Media Transfer Protocol) was introduced.
• The difference with media files, specifically music files, is that they demand much more management.
• Downloading services can require special licensing and a limit on the number of playbacks a music file can have.
• The acquisition, restoration, updating, and backing up of these licenses as well as compatibility issues with file type and compression ratio within these digital music players demanded a more user-friendly and functional approach to file transfers.
• For this reason, you will need to have Windows Media Player 10 or 11 available on your computer to utilize MTP.
• Those with Windows Media Player 9 on their Windows 98 SE, Windows Millennium Edition, and Windows 2000 operating system will need to update using our Download Center.
• We recommend the use of MTP over MSC (the USB mode on your player) because it is more specific to the transfer of music files. To change this setting, press the power button on your device once it’s connected to the computer until the USB icon disappears.

hold down the menu and play button at the same time to reset, should turn it off, then just turn it back on again

As with any issue with this type of digital device, you should always "RESET" the device first (little micro switch - next to the USB port, or on back)...press with a pin (or similar) for 2-3 sec's. I then suggest you fully 'remove' any Samsung Media software (via add/remove programs under control panel). Re-boot your pc, then connect your Z5 into a know working USB port on pc. See if it installs the Z5's driver correctly (ie starts communicating). If this gets it going, you must now download the newest firmware from Samsung's website (download centre), and then save the files into your Z5 (ie overwrite the old firmware). If this fails, then try Samsung directly for further intructions. Good luck.

There may be possible reasons why your Sansa E250 would display an message on the LCD even when you've downloaded files to it: (1) The music file type is not supported by the player. Sansa players support only MP3 and WMA files. To determine what file type your have, right click on the file type and it should display the "properties" dialog box. Check if it is MP3 or WMA. For example, iTunes music files will not work with the player, nor will WAV or MIDI files. (2) Your music files are supported but the bit rate is not within the range that the player supports. Sansa players support MP3 files up to 128 KBPS and WMA files up to 64 KBPS. You may need to use a 3rd party music file editor to convert the files to a supported bit rate (3) You may have saved your music files in a folder and copied the folder to the player. Your Sansa E250 will not recognize folders. Either save them in the root directory or inside the "Music" folder -- your player's default folder for music files. Hope this info helps :)