AoE3 weird problem

Sup guys,

Me and my friend wanted to install AoE3 again to have some fun. We both installed with the same old CD's, and it worked flawlessly for me, both offline and online on ESO (I'm on Windows 7). But my friend got some issues with the game (he's on windows 10). The game in itself works fine, he can play solo and stuff, but when he tries to go multiplayer he gets stuck at the ESO login page. When he enters the ESO username and password and then clicks the button "OK", he can hear the little sound produced when clicking a button in-game, but nothing really happens. He doesn't even get an error message or anything. Clicking OK just doesn't get him any reaction from the game whatsoever. He obviously already tried to launch as admin and he also tried the compatibilty mode. He tried different resolutions but without success. His graphic card is Radeon R9 900 btw, but I don't think the problem comes from that.