SQLSTATE[HY000] [1045] Access denied for user 'admin'@'localhost' (using passwor

I have an message like below, before i used projector and i solved this problem, but i forgot: i remember for this problem i must chane the attribution file from read only to read and write
but i forgot which file

please help me to solve this issue:

SQLSTATE[HY000] [1045] Access denied for user 'root'@'localhost' (using password: YES)
dsn = mysql:host=127.0.0.1;port=3306

Thanks for your quick answer, but my problem is exactly that i have not parameterlocation.php
i have not this file
i check in tool liberary and i didnot find it. last time when i contatct to projeqtor they told me this a problem about unzipping zip file and read only attribution file. i changed attribution to read-write and it works. but this time i have not parameterlocation .php
thanks

this is a first installation after installing my new operation system.
I changed all projeqtor folder from read only to read-write but i saw always the same message about access denied. in first configuration interface i must change anything? about user and password?
Actualy User :root
Pas: mysql