My Coworker, a software engineer, Rich Litz came up with a solution for an mp3 player that won't play anymore because it needs reformatting. Plug the mp3 player into your computer and wait for it to show up as a removable drive, then right click on the drive and choose FORMAT DISK from the drop down list. It may take several minutes as many as 7-10, but eventually the Format Removable Disk diaglog box appears. Choose "FAT32" as the File System and "Default allocation size" as the Allocation unit size, then click Start, again after clicking start there may be several minutes before you see the next dialog box screen, so be patient. This will reformat the mp3 player's flash memory and bring the mp3 player back to its original factory status. The mp3 player's operating system is hard-coded directly onto the chip itself and is not part of the flash memory, so once the flash memory becomes readable again the mp3's operating system is able to work with it once more and the device functions as normal.
Sean Jefferson, May 2007