If you can't restore your iPod using the iTunes method above because you're prompted for a passcode, or you've never used your iPod with iTunes before, you'll need to put your iPod into Recovery Mode. This will allow you to restore it without needing the passcode. Because you are using Recovery Mode, you won't be able to create a backup of your iPod before restoring it. You will lose all data on your iPod. You'll need to start the procedure with your iPod powered down completely. Press and hold the Power button and swipe the Power slider to turn it off. The only way to use Recovery Mode is to connect it to a computer and use iTunes. You don't have to have synced your iPod with that computer in the past. If you don't have iTunes installed, you can download it for free from apple.com/itunes/download. Don't release the buttons after you see the Apple logo. Continue holding the buttons until you see the iTunes logo on your iPod's screen. If your iPod's Home button doesn't work, download TinyUmbrella from firmwareumbrella.com, run the program, then click "Enter Recovery Mode." This will begin the restore process for the iPod. If this process still doesn't let you restore your iPod, see the next section. Once the restore process is complete, you'll be prompted to setup your iPod as if it were new. If you have an existing backup, you'll be able to load it.

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Write a summary of the previous text in Vietnamese:
Áp dụng phương pháp này nếu iTunes hỏi mật mã. Tắt nguồn iPod. Kết nối iPod với máy tính. Mở iTunes. Nhấn giữ nút nguồn và phím Home. Nhấp vào "Restore" ở cửa sổ hiện ra trên iTunes. Cài lại iPod.