SQLSTATE[28000] [1045] Access denied for user 'root'@'localhost' (using password: YES) Error

[Matthias Egger]

Hi guys,

I keep getting this error:

SQLSTATE[28000] [1045] Access denied for user 'root'@'localhost' (using password: YES)

And I obviously don't know how to fix it.
I have installed MySQL, Apache2, PHP and phpMyAdmin.
I get t his error when trying to enter my ip/main.php page of the website.
When accessing the ip/phpmyadmin page everything goes well.

Can anyone explain this? Thank's in advance guys.

Kind regards,

Matthias