Knowledgebase
How to change the default store view in Magento
In Magento you can create more than one store view within a store. Customers can choose the store view from a drop-down menu on the frontend. Usually store views are used to display the site in different languages. In case you have added two or more store views one of them is set to be the default store view. This is the store view that's initially displayed when a user visits your site.
You can change the default store view to any of the existing store views that you have created. To do this, log in to the admin panel of your Magento and go to System menu>Manage Stores. On the page that opens you'll see a table with the existing websites, stores and store views. Click on the name of the store (not the store view) to which the store view belongs. A page with some settings will be displayed; set the Default Store View drop-down menu to the store view that you want and click on the Save Store button.
If you need more information on store views and how to add them check out the article or tutorial on adding store views and creating a multilingual Magento site.