My ipod 3rd generation won't connect to itunes, I've tried everything possible to sort it out but does anyone have any other ideas?

This evening I upated the software on my ipod and when i tried to reconnect it to itunes it didn't recognise it. I've tried every single way to fix it from apple support and the forums but nothing is working. Occasionally my ipod will let me reset it but it won't let me hold down the play/pause button and select button to bring up the other options.

My computer recognises that it is connected as I can open it in my computer so as far as I can tell there is nothing wrong with the USB connection.

I've checked my firewall settings. I've tried uninstalling itunes and reinstalling. I've tried restarting apple mobile device. I've restarted my laptop and itunes countless times.

Does anyone have an idea I haven't tried?

I use windows 7 by the way.