im trying to download os el capitan and it keeps telling me device or computer could not be verified what does that mean

Hi,

Quit the App Store.

Then open the Finder.

From the Finder menu bar click Go > Go to Folder

Then copy / paste the following:

/Library/Preferences/SystemConfiguration

Click Go then move the Networkinterfaces.plist file from the System Configuration folder to the Trash.

Restart your Mac then try downloading El Capitan.

If the above doesn't work, try downloading in another admin user account.