im sorting out an iphone for a friend but as it turned out the iphone he bought was on 2.0 firmware which was a bit of a bummer so i try to get it to go into dfu mode manually and it wont so i plug it into my computer and use ziphone to get it into dfu. it goes into DFU and i try to continue with the downgrade prosedure but itunes wont recognise the iphone. i plug it into my computer it makes three dings like the noise when u plug a new piece of hardware in and then nothing.

in device manager it shows it under the usb devices like below

thenw when i unplug it to try and restart it or force restart it sits there looping turining on and off comping up with the usb to iTunes picture over and over

please help i cant think of anything and ive tried tons of different things