Due to you using cPanel this could be causing the problem, but do what Kryptos is saying and if it still doesn't work I would just double check to see if a copy of config is in the install folder and also make sure you delete it.
All you need to do is create a database create a user, add it to each other, Give it permissions, Then edit the config file and put in yourhostingaccountname_databasename. Then, yourhostingaccountname_username. And your password, It's simple.
And @ Kryptos, You don't need the install folder, As it rebuilds have the tables lol.
Also @ Kieren, I used Obbo on cPanel, So It should cause no problem what so ever.