SureAI

Hi, I had a Skyrim version with lots of mods, so I removed everything, deleted every single mods, and started a fresh new install.
But it's still not working. When I launch the game I got the background screen, and instant crash, no message or nothing.

Do I have to install the game in english ? Or is it ok if it's in french and I install Enderal over it ?

Makes no difference. I have installed the english Enderal over my german Skyrim. Works perfectly.
It could be that your installation package is damaged. Reload it (We recommend torrent).
Make sure all mods/ENBs are disabled in your Skyrim installation.
Watch this video and follow the shown steps.