You should not partition, format, or change the formatting of iPod's hard disk using Disk Utility, Windows Explorer or other utility unless you are performing troubleshooting steps that require this step.
iPod, iPod mini, and iPod shuffle cannot play music if you format or partition the hard disk.
iPod only works (as a music player) when its hard disk is formatted for the appropriate platform using the Mac OS Extended (HFS Plus) or FAT32 formats. Do not reformat the disk using Mac OS Standard (HFS), New Technology File System (NTFS), or UNIX File System (UFS) formats.
Whether you use a Mac or Windows, iPod shuffle only works (as a music player) when its disk partition is formatted as FAT32 format.
If iPod's hard drive was partitioned, formatted, or the format was changed, use the latest version of the iPod Updater application to restore iPod iPod back to its factory condition.
Warning: The restore process cannot be undone. All of your songs and files will be deleted. Always make a backup of your important data.