My Win 7 don't recognize my IPod 5.

iOS: Device not recognized in iTunes for Windows

I would start with

Removing and reinstalling iTunes, QuickTime, and other software components for Windows Vista or Windows 7

Run this to help if it identifies the cause

iTunes for Windows: Device Sync Tests

Have you tried on another computer to help determine if you have a computer or iPod problem?

Do you have iTunes 11.1 on the computer:

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.

- Try on another computer

- If still not successful that usually indicates a hardware problem and an appointment at the Genius Bar of an Apple store is in order.

Apple Retail Store - Genius Bar

Error 2000-2009 (2001, 2002, 2005, 2006, 2009, and so on)

If you experience this issue on a Mac, disconnect third-party devices, hubs, spare cables, displays, reset the SMC, and then try to restore. If you are using a Windows computer, remove all USB devices and spare cables other than your keyboard, mouse, and the device, restart the computer, and try to restore. If that does not resolve the issue, try the USB issue-resolution steps and articles listed for Error 1604 above. If the issue persists, it may be related to conflicting security software. If the errors persist on another computer and known-good USB cable, the device may need service.

The "device may need service" means a hardware problem. In that case make an appointment at the Genius Bar of an Apple store.

Apple Retail Store - Genius Bar

If you got same error on another computer then:

The "device may need service" means a hardware problem. In that case make an appointment at the Genius Bar of an Apple store.

Apple Retail Store - Genius Bar