And I am receiving the following error when trying to install the upgrade.

MySQL error!

Error establishing a database connection!

(Access denied for user: 'demouser@localhost' (Using password: YES))

1. Are you sure you have typed the correct user/password?
2. Are you sure that you have typed the correct hostname?
3. Are you sure that the database server is running?

Can anybody tell me why this is happening? Do I need to create an entirelyl new database, separate from the one I was using for the previous version?