Sounds like you have a problem or network or system installation itself. You can do two things.
1. Ask if the poster, but I guess you formatted and reinstalled the equipment.
2. If you copy, restore your computer.
If you have a network problem on that computer, check the network configuration and if you arrive (either because you have a firewall on the connection or proxy that prevents certain machines or a problem with DNS) to the following teams:
swscan.apple.com, swquery.apple.com, swdownload.apple.com, swcdn.apple.com and makes it to port 80 of these machines.