How to restore backup firmware 3.13?

No, you must pirate the 3.1.3 software to restore from it.

I'm sorry to say this, but I can't really help you for ethical reasons. You should have done your homework before updating to 4.0.

 

What?

 

You want to reverse to a older version firmware on your touch ? This sort of thing is not supported by Apple, but this is how it can be done......

I did this recently. It was easy. Though 3.1.3 did not work for whatever reason. 3.1.2 did work properly. I made the mistake of using 4.0 as well.

First you need a copy on your computer of the firmware file you want to install on your touch. Download that from here.....http://www.felixbruns.de/iPod/firmware/

Then follow these steps. It pretty easy.......http://lifehacker.com/5572003/how-to-downgrade-your-iphone-3g[s] -from-ios-4-to-ios-313

You'll be out of 4.0 in no time.......

 

+1, ive heard that 3.1.3 never works, or at least i havent seen someone downgrade to it.

 

3.1.2 will definitely work and is available out there. Thing is you'll lose all of your app specific data when you do this and have to reset all of your information on the device. You can easily restore your apps however. Pretty crazy that Apple does this frankly: they put out of piece of crap of an os update and prevent you from reversing it. To the other poster that blamed the person for not researching the update first: come on; do we have to research an update before applying it? It's not the user's fault; it's Apple's fault. Period.