Back in the Giulia
AO Silver Member
Join Date: Jun 2007
Location: United Kingdom
County: Greater Manchester
If you are having problems, it's always going to be better using a USB or a DVD so you can try things several times without needing to download it each time.
I had a couple of issues with one of my PCs where the upgrade always failed. If the problem isn't with the download, it will still fail using a USB.
If it fails again, you need to make a note of the error code so you can search for a possible answer on the Internet. Somebody, somewhere has usually come across it before.
With mine, I got one error and fixed it by deleting some files after searching for the error. When I tried it again I got a different error which was then fixed by disabling a wireless card and now it's worked.