Dfu. Tool.

hey,
what is DFU tool and what it is used for?

can anyone suggest me?

If you had a little effort and did a search on "DFU Tools", the first thread you would find is the main topic. In it Err0r explains:

Originally Posted by Err0r

DFU Tool is applied when the MP3 player can't connect to the computer or ceases function properly. Sometimes this is included in the bundled CD, check if you have it before downloading.

DFU means Device Firmware Upgrade.

If your player cannot be resetted this is your last resort to upgrade the firmware (external) and save your player.