Try this; goto add remove programs in control panel and uninstall ESO. Then go to you program files x86 and manually delete the zenimax or ESO folder. Restart computer. Reinstall from disk or launcher. Try it then.
if still unable, might have a couple stuck registry keys, but I'm not going to take you there. At that point, contact their support.
good luck
"Every man dies, not every man really lives." ~ William Wallace