Xperia U software update problem

[Itsloner69]

Please help! 
I tried updating my phone via PC companion at first, but it wouldn't move on from the part where I had to press the lower volume key. 
Then I downloaded Sony Update Service, I go to the "connect" step and I follow the steps but it still doesnt work. 
This is where I'm stuck. Please help, I;ve been trying to update my phone since the morning.  

[Uliwooly]

restart your PC > disable your firewall and antivirus > run SUS > turn off your Xperia U > press and hold volume DOWN > then connect the usb cable > do NOT release volume down > wait > wait > wait