I am getting the above error when I try to install ESO PTS from the launcher. I am assuming I need to move the PTS folder, but I have no idea where it is or how to find it.
The PTS folder installs itself in same directory as the Live game folder. Look there first.
Failing that do a search for folder, or use something like Search Everything (you would need to download that app, it doesn't come with Windows) to find it.