Database Error: Unable to connect to the Database: Could not connect to MySQL. I just download Joomla 1.61 through Microsoft web matrix and run the index.php and receive this error. nothing change anywhere. all information entered during the installation and its generate automatically.
YOu are so lucky I have been having exactly the same problem on my joomla site so I contacted my host provider and they sent me this link which was very useful: http://dev.mysql.com/doc/refman/5.5/en/too-many-connections.html
If you see unable to connect to the database, check username and password of user of your database. If you forget it, go to phpmyadmin and there look for login and password. For example jos_users
I don't know if you are having the exact same problem as me but I had to change the number of connections I have going to my database due to the volume of traffic I get to the site. Ask you host how you can extend the number of connections, if not hit me back.
In your root folder, check your config.php file. Make sure that matches your DB, user and password set up in your hosting environment