"Disk cannot be read from or written to" when syncing iPod or "Firmware update failure" error when updating or restoring iPod

When you sync your iPod with iTunes, iTunes may display an error message that reads:

"Attempting to copy to the disk failed. The disk could not be read from or written to."

When you update or restore your iPod, you may see this error:

"Firmware update failure. Disk write error."

These errors can happen with any iPod.

These errors can occur anytime iTunes can't read information from or write information to the iPod. Here are some things that can cause this.
Outdated operating system software

Make sure you have the latest updates for your operating system, which may include improvements for device connections. For example, many USB and FireWire improvements have been included in Windows Service Packs. Check for Mac OS X downloads here. Check for Windows updates here.
Computer needs updates

Make sure you have the latest updates available for your specific computer model (or components for home-built PCs). These are usually available for download on the support website for the maker of the PC (or component). Many USB updates are listed as "Intel chipset" or just "chipset" updates on PC manufacturer's support and download websites.
Software interference

Some software can interfere with iTunes, making it unable to write files to your iPod. Think about what software you have installed, and try disabling any add-ons that might be interfering with iTunes. Check your suspected software's documentation or contact the software maker if you need assistance with disabling the application.
Damaged files

If one of your music files or photos is damaged, iTunes may display one of these errors when transferring that file to the iPod. If you identify a file that is causing the error, try deleting that file and reimporting it from a backup file or from the original source. You may be able to repair files by repairing the disk (see the solutions in the next section).
Unregistered .dll files (Windows)

Malware or other software may cause an issue with the digital signing of Windows XP drivers. First try restoring the iPod using the latest version of iTunes.. If you are unable to restore it or the symptom reappears, follow the steps in this document.
Damaged disk structure

These errors can also appear if the format of your computer's hard drive or your iPod disk is damaged.

To repair your computer's hard disk—Mac OS X users, read this article for instructions. Windows users, search the Help system in Windows for chkdsk to get more information on checking and repairing the disk structure.

To repair an iPod disk—Restore the iPod or iPod shuffle using the latest version of iTunes. Warning: Be sure to back up your data before restoring an iPod. The restore process cannot be undone. All of your songs and files will be deleted.
Corrupt iPod photo Cache

If you're getting the error when transferring photos to an iPod photo, try deleting the iPod photo Cache and then starting the photo sync again.
Lost connection

Make sure that the connections from your computer to the iPod are snug and do not wiggle or come loose during transfers. For example, if you use the wrong size dock for your iPod, it can put strain on the connectors and cause a bad connection. See these articles for more information:

* iPod Dock: Specifications
* Learn about iPod photo Dock

Conflict with third-party hardware

Third-party USB or FireWire devices may also interfere with iTunes' ability to communicate with your iPod. Remove all USB and FireWire devices except the keyboard and mouse before reconnecting your iPod to the computer.
Bad hardware

Hardware failure or non-compliant hardware can cause these errors. This could be an issue with iPod hardware or with the cable or dock you're using, but more often it's an issue with the USB or FireWire card or interface in your computer. Some USB and FireWire interfaces just don't work very well. If you isolate the issue to the USB or FireWire interface in your computer, you may want to try a different port, get the computer serviced, or replace the card or interface with a better one.

If you isolate the issue to an Apple-supplied cable or dock, or the iPod itself, you can get it serviced here.

http://docs.info.apple.com/article.html?artnum=301267

Windows confuses iPod with network drive or hard drive and may keep iPod from mounting or songs may seem to disappear

If the drive letter after iPod is mapped to a network drive or is a drive letter typically used by a hard drive, both Windows Explorer and iTunes may exhibit strange behavior in relation to the iPod.
Symptom

One or more of the following occurs:

* iPod does not show up in iTunes or as disk in Windows Explorer.
* iPod does not show up as disk in Windows Explorer (even though disk mode is enabled on the iPod).
* iTunes and Windows Explorer report the wrong amount of available space on iPod.
* No songs appear on the iPod after an apparently successful update from iTunes.
* Music copied to mapped network drive instead of iPod.
* The iPod setup assistant appears in iTunes every time the iPod is connected.
* iTunes displays the "iTunes has detected an iPod in recovery mode - Use iTunes to restore" message even after the iPod has been restored.
* The wrong iPod name displays in the iTunes source list.

Products affected

* iTunes for Windows
* iPod (all models)
* Microsoft Windows 2000
* Microsoft Windows XP

Solution

This issue is documented in Microsoft Knowledge Base document 297694, "New Drive or Mapped Network Drive Not Available in Windows Explorer".

Changing the drive letter of your network volume should resolve the issue. If you are unable to change the drive letter of the network volume because your programs depend on a specific drive letter, then you can use the following steps to change the drive letter of your iPod instead.

Important: Changing the iPod drive letter may not affect what letter the iPod uses on subsequent connections, so it is not the best long-term solution. If you are unable to change the drive letter of your mapped network drives, contact your system administrator.
Change the Drive Letter

1. Open the Control Panel.
2. Double click on Administrative Tools. Note: If you don't see Administrative Tools, look at the left column in Control Panel for a link that says, "Switch to Classic View," and click it.
3. Double click on Computer Management.
4. In the left column, click on Disk Management.
5. Locate the iPod and right click on it, then click Change Drive Letter and Paths.

#Click the Change button.
# Use the drop-down menu to select a new drive letter. Note: Make sure to choose a new drive letter that is not already assigned to a network drive. The drop-down menu will display all available letters that are not assigned to a physical drive. Drive letters that are assigned to a network volume will still be listed here. It is also a good idea to assign a drive letter other than a, b, c, or d, as these letters are usually reserved for other system drives.
# Click OK.
# Click Yes on the confirmation dialog.
# Close the Computer Management window.
# Restart your computer.

http://docs.info.apple.com/article.html?artnum=93499

Windows confuses iPod with network drive or hard drive and may keep iPod from mounting or songs may seem to disappear

If the drive letter after iPod is mapped to a network drive or is a drive letter typically used by a hard drive, both Windows Explorer and iTunes may exhibit strange behavior in relation to the iPod.
Symptom

One or more of the following occurs:

* iPod does not show up in iTunes or as disk in Windows Explorer.
* iPod does not show up as disk in Windows Explorer (even though disk mode is enabled on the iPod).
* iTunes and Windows Explorer report the wrong amount of available space on iPod.
* No songs appear on the iPod after an apparently successful update from iTunes.
* Music copied to mapped network drive instead of iPod.
* The iPod setup assistant appears in iTunes every time the iPod is connected.
* iTunes displays the "iTunes has detected an iPod in recovery mode - Use iTunes to restore" message even after the iPod has been restored.
* The wrong iPod name displays in the iTunes source list.

Products affected

* iTunes for Windows
* iPod (all models)
* Microsoft Windows 2000
* Microsoft Windows XP

Solution

This issue is documented in Microsoft Knowledge Base document 297694, "New Drive or Mapped Network Drive Not Available in Windows Explorer".

Changing the drive letter of your network volume should resolve the issue. If you are unable to change the drive letter of the network volume because your programs depend on a specific drive letter, then you can use the following steps to change the drive letter of your iPod instead.

Important: Changing the iPod drive letter may not affect what letter the iPod uses on subsequent connections, so it is not the best long-term solution. If you are unable to change the drive letter of your mapped network drives, contact your system administrator.
Change the Drive Letter

1. Open the Control Panel.
2. Double click on Administrative Tools. Note: If you don't see Administrative Tools, look at the left column in Control Panel for a link that says, "Switch to Classic View," and click it.
3. Double click on Computer Management.
4. In the left column, click on Disk Management.
5. Locate the iPod and right click on it, then click Change Drive Letter and Paths.

#Click the Change button.
# Use the drop-down menu to select a new drive letter. Note: Make sure to choose a new drive letter that is not already assigned to a network drive. The drop-down menu will display all available letters that are not assigned to a physical drive. Drive letters that are assigned to a network volume will still be listed here. It is also a good idea to assign a drive letter other than a, b, c, or d, as these letters are usually reserved for other system drives.
# Click OK.
# Click Yes on the confirmation dialog.
# Close the Computer Management window.
# Restart your computer.

http://docs.info.apple.com/article.html?artnum=93499

Copying iTunes Store purchases from your iPod to a computer

If you purchased items from the iTunes Store and the only place you have them stored is on your iPod, you can transfer them from your iPod back to any computer that is authorized for your iTunes Store account using iTunes 7 or later. This feature adds an extra layer of protection against losing your valued purchases.

If you want to transfer iTunes Store purchases from an iPod to a computer, be sure to authorize the computer before connecting the iPod. To authorize, follow these steps:

1. Open iTunes.

2. From the Store menu, choose Authorize Computer.

3. In the dialog that appears, the Apple ID button is selected by default. If you have an AOL account, select AOL.

4. Enter your Apple ID or AOL screen name and password, then click the Authorize button.

If the iTunes Store purchases on your iPod were purchased with multiple accounts, you will need to authorize the computer for each one.

To transfer iTunes Store purchases from your iPod to a computer, follow these steps:

1. Connect your iPod to the computer. Since your iPod is synced with another iTunes library, the following dialog will appear:

2. Click the Transfer Purchases button.

iTunes will begin copying any purchases made with any account that the computer is authorized for.

If when you connect your iPod you are not prompted by the dialog above, it could be that the option "Do not ask me again" was previously selected. Fortunately, there are two more ways you can copy your purchases from your iPod.

After connecting your iPod to the computer and the iPod appears in iTunes, you can choose Transfer Purchases from iPod from the File menu.

Or you can right-click (Windows or Mac) or Control-click (Mac only) your iPod in the iTunes Source list, then choose Transfer Purchases from the shortcut menu that appears.

Please note that this feature only works for items that were purchased on the iTunes Store. Any items imported from audio CDs or acquired from other sources will not copy from your iPod to the iTunes library.

http://docs.info.apple.com/article.html?artnum=305465