My site url is http://deepakanand.vndv.com

This is the error I am getting when I try to install Wordpress by opening /wp-admin/install.php

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"Error establishing a database connection"

This either means that the username and password information in your wp-config.php file is incorrect or we can't contact the database server at localhost. This could mean your host's database server is down.

* Are you sure you have the correct username and password?
* Are you sure that you have typed the correct hostname?
* Are you sure that the database server is running?

If you're unsure what these terms mean you should probably contact your host. If you still need help you can always visit the WordPress Support Forums.
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These are the changes i made in the wp-config file:

define('DB_NAME', 'deepakanand_myschema'); // The name of the database
define('DB_USER', 'deepakanand_deepakanan'); // Your MySQL username
define('DB_PASSWORD', '*******'); // ...and password
define('DB_HOST', 'localhost'); // 99% chance you won't need to change this value

Please advise.

I guess it is a database connection error.
When I did this:

var_dump(mysql_connect('localhost', 'deepakanand_deepakanan', 'password'));

This is what I got:

Warning: mysql_connect() [function.mysql-connect]: Access denied for user 'deepakanand_deep'@'localhost' (using password: YES) in /www/vndv.com/d/e/e/deepakanand/htdocs/debug.php on line 2
bool(false)

Why is this happening, please advise

Bingo !! the problem is long user names.
I created a 3 letter user-name and it is working now