Magento-1.9 – Fix SQLSTATE[HY000] [1045] Access Denied for User ‘root’@’localhost’

Look in the /tmp/ folder (the one on the root of the server, not the one in your vhosts document root) and see if there is a magento folder. If there is, delete it, your cache is stored here if your webserver didn't have write access to var/cache on first request.

If that doesn't work, try running the query SELECT * FROM core_config_data WHERE value LIKE 'http%'; incase you missed one of the URL settings.

Wrong username and password or invalid access rights to you MySQL server.

Check app/etc/local.xml and verify your credentials.

If you need to reset you MySQL password you have to access your MySQL shell and use the following command (replace with correct information):

GRANT ALL PRIVILEGES ON yourdbname.* TO 'pctekcom_magento'@'127.0.0.1' IDENTIFIED BY 'yourpassword';

NOTE: MySQL username and password, NOT Magento username and password.

If you have phpMyAdmin you can use the "users" function.

Also try using localhost instead of 127.0.0.1 in your app/etc/local.xml, sometimes it fails the reverse lookup for localhost.