Ok my friend bought ESO Tamerial Unlimited Gold Edition through Steam and is unable to access the game - what does he need to do to be able to play.
Does he need to re-purchase the game?
I am afraid we will need a bit more information to help you. What do you mean by "unable to access"? Does the game launch at all? Does he get an error when he tries to log in?
If he's already installed the game, he needs to go to his Steam Library and click the 'play' button which will open the launcher. To log into the game he needs to use his Steam username and password.
The game installs like normal - but in the ESO launcher it says he needs to reinstall the game and it needs an additional 87gb.
He does not have Morrowind. He bought the GOLD edition when it was on sale from Steam
The next thing your friend can try is completely uninstalling ESO from their PC and then going through the install once more. Uninstall directions can be found in the help article linked below.