WordPress stores two addresses inside the database. These determine where your blog files are, and where the main index is. On a normal install, these addresses are the same.
There are two occasions where you will need to access the database to alter one or both of these settings:
1. If you have tried to alter the Blog URL or WordPress URL in Settings, and an error has occurred.
2. If you have moved to a domain/subdomain with a different name.
BACKUP your database before you begin and store the backup off your site server, like on your hard drive. See: Backing Up Your Database.
It should be possible to fix the site URL using a new feature –
Add these two lines to your wp-config.php, where “example.com” is the NEW location of your site.
Change your IIS settings to reflect the new URL.
If you need to import content from another wordpress blog, create new users during import and then adjust user privileges afterward.
That should be it.