First off I tried OTA at about 18:50. Apple said they needed 2.9 Gig free, my 4 only has 2.6 Gig free.
So back to the PC.
iTunes insisted on updating, I've been running 10 as I hated the new look and feel, but will just have to give up on that now.
Once iTunes, iCloud were updated the PC insisted on a reboot, then iOS 7 failed to download, said I didn't have permission to download it?????
Came back to the PC about a hour later and this time it decided to play ball. Update is now running, the verification process took ages, guess the servers are a bit busy. Have passed that now, progress bar on the phone is about 25% across the screen and moving v slowly, but the progress bar on iTunes says it has nearly done.