If anyone is having difficulty with the OS5 download and uses Kaspersky anti-virus, be sure to disable it. I struggled for days and was getting a message that the "network connection" timed out immediately after the download completed. I finally tried it with an ethernet connetion to my modem and I got the same message. After talking to Apple on the phone and trying several things, I ended up getting a different error code at the same time that referenced a code that the Apple Tech diagnosed as interference from the antivirus. I then disabled that and the download process was flawless.