My ipod touch, 4th gen shuts down and freezes. What can I do?

Try:

- iOS: Not responding or does not turn on

- Also try DFU mode after try recovery mode

How to put iPod touch / iPhone into DFU mode « Karthik's scribblings

- If not successful and you can't fully turn the iOS device fully off, let the battery fully drain. After charging for an least an hour try the above again.

- If still not successful that usually indicates a hardware problem and an appointment at the Genius Bar of an Apple store is in order. If defective, within warranty and not aboused Apple will exchange it at no cost.

Apple Retail Store - Genius Bar

Error 13, 14, 35 and 50 (or -50)

These errors are typically resolved by performing one or more of the steps listed below:

1. Perform USB isolation troubleshooting, including trying a different USB port directly on the computer. See the advanced steps below for USB troubleshooting.
2. Put a USB 2.0 hub between the device and the computer.
3. Try a different USB 30-pin dock-connector cable.
4. Eliminate third-party security software conflicts.
5. There may be third-party software installed that modifies your default packet size in Windows by inserting one or more TcpWindowSize entries into your registry. Your default packet size being set incorrectly can cause this error. Contact the manufacturer of the software that installed the packet-size modification for assistance. Or, follow this article by Microsoft: How to reset Internet Protocol (TCP/IP) to reset the packet size back to the default for Windows.
6. Connect your computer directly to your Internet source, bypassing any routers, hubs, or switches. You may need to restart your computer and modem to get online.
7. Try to restore from another known-good computer and network.

You get of of DFu mode (and recovery mode) by restoring the iPod via iTunes.