New local WAMP Machine Error Establishing database connection

What you have done looks correct, but obviously isn’t 🙂

Were you using the WAMP default database user and password on the XP system? That is, root and empty (no password), OR did you create your own database user on the XP system? If so, you will have to do the same on the 8.1 db as well.

A couple things:

– is the WAMP system tray icon ‘green’

– are you able to successfully see the WAMP start page when you enter http://localhost

The only thing that I can suggest is to ‘triple check’ the values in your wp-config. Something is not correct in either the values there or the db name in the 8.1 db. As you probably know, all it takes is a space in one of the values to generate that error 🙂

I’ve tried the raw and generated passwords from the wp_users password
database variable in the wp-config file and neither work

The values in the wp_user table are for the WordPress login, and NOT for the database 🙂

Given the name of the database is wordpress, this is what your wp-config should look like:

/** The name of the database for WordPress */
define('DB_NAME', 'wordpress');

/** MySQL database username */
define('DB_USER', 'root');

/** MySQL database password */
define('DB_PASSWORD', '');

/** MySQL hostname */
define('DB_HOST', 'localhost');