Hi; I am using windows 7, and have an ipod touch 4g. Itunes has stopped seeing it.

when I go to restore the ipod, it gives me an error 1604. I have restarted my computer, switched usb ports, verified usb 2.0, updated itunes, and switched cables, but still get the error. Now the ipod will only power up to the 'connect to itunes' screen unless I put it in the mode it needs to be in to be restored. What next?