Hello, this is a french forum, you'll likely get more helpful replies to your issues on
the english Ubuntu forum.
Anyway, the user created during installation is not an admin account but should be in the list of sudoers that allows the use of the sudo command to get temporary admin rights. What happens when you use sudo (e.g.
sudo apt-get update to reload the repos list)? Error message or does it ask for your password?
If your account can't use sudo, something went wrong during installation, but it'd be a bit peculiar.
