update iphone 4 network connection timed out

Hi

I have been trying to update my Iphone 4 from the IOS software version 4.3.5 to the latest version but have become frustrated at none of the proposed solutions being successful so i'm hoping someone can point me in the right direction. I'm trying to do this through a PC with Windows 7 and an internet connection that appears to do all it should, albeit not at a frightening pace.

Some points so far:

- the age of my current version means the update through the phone alone is no longer available

- I have updated itunes to latest version but when i then try to update phone though itunes, it says network connection timed out.

- during all this, I have disabled my firewall/anti-virus and all other aspects of my Kaspersky 2013 protection software

- I downloaded the relevant IPSW files directly to my PC but when this is installed through Itunes, it again results in an error.

- I went to the Apple Store Genius Bar yesterday who said it will be fine if I fully uninstall and reinstall itunes. I followed the apple guide to doing this, but when i then go back to trying to update the phone, it still comes up with the network connection being timed out.

If anyone has any thoughts it would be much appreciated as my local Apple Store isnt that local and Im hoping to avoid having to make the lengthy journey again.

Many thanks in advance,

Jonathan