If you're not able to format or get a USB drive to be recognized in the TD-25, it could be due to data that may have been previously embedded on the drive. Formatting the USB drive in the computer using the FAT 32 registration will usually help. Here's how to format a USB drive in a PC computer:
1. Insert the USB drive into an available USB port on your computer.
2. On the computer, click "Start" (Windows symbol in lower left corner) and then "Computer."
3. Click on the external drive -- For example; "Removable Disk (E:)" -- to highlight it.
4. Right click on the external drive and then click "Format."
5. When the "Format Removable Disk" window opens, click the File System down arrow, and then click "FAT 32."
6. Click Start.
When the format process is complete, eject the drive from the computer and then format it in the TD-25.
Here is a link to the Steps on how to format a USB drive in the TD-25: TD-25: Formatting a USB Memory Drive