ESO account

I installed the game in steam but with an other Account so Today i buyed that game on my own account I cant play multiplayer becouse he starts the key from the oter account i deleted it install it new Nothing help nothing i just wanted to create an account and play it online

how can i change the Key in steam

All you need to do is run the registry cleanup script: http://agecommunity.com/downloads/AOE3_Win7_Registry_101.zip