One of the advantage of using CMS is we can modify it to suit our design needs,WordPress gives you  great degree of flexibility to change even the core functions of the system.One such Example is modifying WordPress Login page.

Why You need to Modify WordPress Login Page ?

The only reason I could see is,to create a Perfect Brand,When your website is unique then you don’t want to have same Login page as millions of other WordPress users have.

Lets Look at the Default Login page

default-login-page

You can also note that when you click the WordPress logo it will take you to http://wordpress.org/.So we need also change the default URL to your blog URL.Lets find How to do that

Change Wp-Login Logo

function my_custom_login_logo() {
echo '<style type="text/css">
h1 a { background-image:url(http://techiestuffs.com/wp-content/uploads/2012/06/logo-admin.png) !important; }
</style>';
}

add_action('login_head', 'my_custom_login_logo');

Copy the above code and paste it in your current theme’s Function.php.You need to replace http://techiestuffs.com/wp-content/uploads/2012/06/logo-admin.png with your Custom Logo URL.

If you are using Thesis theme you can paste above code in custom-functions.php

Change the Logo destination URL

function wpc_url_login(){
return "http://techiestuffs.com/"; // Replace with your Blog URL
}
add_filter('login_headerurl', 'wpc_url_login');

Now copy and paste the above code in your current themes Function.php.

Now clear your browser cache and WordPress cache if you use some caching plugins such as W3Total Cache/WP super cache.Now Logout and visit your blog login page(http://yoursite.com/wp-login.php).

modified-login-page

TIP : By default the Logo size is 326*69px,So design your logo with this size.