For last maybe year I've had problem with ESO launcher. It works fine for month or two, then gets "lazy" for couple weeks, then spontaneously gets normal again. Tried reporting to ESO support, but there wasn't any solution they could provide. We just went back and forth until launcher fixed itself on its own.
I'm running Steam version of the game on 64 bit Win10. What happens is, that suddenly the launcher takes several minutes to load. First there is black rectangle, then stripe of top of the window, then bit wider stripe of the top, until there's whole window. Then the news load in, but not the preview wih the pictures on the right. Then finally "play" becomes clickable. Have to hover mouse above the button for 1 - 2 seconds to get registered and after clicking there is delay registering that too. Once I click "play" the game starts and runs completelly normal.
Was going to wait this out as always, but then todays update hapened. It runs sooo slooow. Two hours in and it's only at 19%, freezes constantly, window jumps all over desktop when clicked (now it went randomly to right top corner, only tiny bit is visible and can't be grabed and moved anywhere). It is disaster. Won't be getting in game today, that is clear. No idea about next day.
If anyone has any idea how to fix this mess, or know workaround how to update game / get in game without launcher, it would be much appreciated. ESO support is unfortunatelly completely useless in this case.