Use the following steps to delete your network preferences.
Important: You must be logged in as an administrator.
- Click the Finder icon in the Dock.
- Choose Go to Folder from the Go menu.
- Type /Library/Preferences/SystemConfiguration
- Copy the file networkinterfaces.plist to the desktop (to make a precautionary backup).
- Delete the file "networkinterfaces.plist." from SystemConfiguration.
- Restart your Mac.
- Create new location in Network preferences, in System Preferences.
Once your computer has restarted, you will need to refresh your network settings to be able to connect to the Internet again:
- Choose System Preferences from the Apple menu.
- Choose Network from the View menu.
- From the Location pop-up menu, choose "New Location".
- Type a name for your location and click OK.
- Click the Apply Now at the bottom right to accept the changes.
If your network connection requires any special settings, you will need to enter them again.
Once you have made these changes, you should be able to connect to the Internet, open App Store, and try your OS X Lion purchase or download again.
This issue may occur if your Mac's Ethernet port is damaged or inoperable, even if you aren't using Ethernet to try to download Lion.