Time ago i had some troubles trying to use my xbox 360 controller in TESOnline, wandering on all internet i couldn't find any solution, so being the stubborn as i am i tried to "seek" what was the problem and i had some luck.
If you have the same problem i suggest you to look the game folder, (C:\Program Files\Zenimax Online\The Elder Scrolls Online\game\client) and look for the next archives.
• x360ce.exe
• xinput1_4.dll
• xinput1_3.dll
• xinput1_2.dll
• xinput1_1.dll
• xinput9_1_0.dll
These are archives of the "Xbox 360 Controller Emulator" great program but its enter in conflict with TESOnline, because the game have his own recognition program and it will desactivate if this files are in the game. My problem was fixed when a cut those files and today i can play with my controller as much as i please.
This is my solution, try it if you have the same problem.
bye, and good luck.