AppleCare KnowledgeBase Document:
“Some Windows-compatible computers may be able to connect to iPod (with Dock Connector) using a USB 1.1 connection, but this is not a recommended configuration.
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You may be able to connect an iPod (with Dock Connector) model to a Windows-compatible computer using a USB 1.1 connection, but this is not recommended because the connection is too slow to synchronize music.
For best performance, connect iPod to your computer using USB 2.0 or FireWire.
