Definition of the Media

When you browse for an image from an Image field or Rich Text field in Sitecore, you get to see the Media Browser. In version 6 you would just see a tree view, from version 7 you get a search view as default. The tree view is also there, but you need to switch tabs.. Some people prefer the tree view though and want that as default.

Sitecore 7.0

In Sitecore 7.0 you can alter the default tab in the Media Browser by editing the \sitecore\shell\Applications\Media\MediaBrowser\MediaBrowser.xml. You will see a Tabstrip with 2 tabs ("MediaLibraryTab" and "MediaTab"). The first tab is the default, so by switching them around you can set the MediaTab ("browse") as default.
The best way to handle your new file is to place it in the "\sitecore\shell\Override" folder.

The result will look like this:

Sitecore 7.1

In Sitecore 7.1 they changed the Media Browser. The search pane even appears to have a bug (the datasource if provided is not taken into account), but that's not our focus here.
The top of the Media Browser now looks like:

Switching the panes can be done with the buttons on the right (above the search field). Setting the default to the tree view however is again possible: in order to use the tree view as a default view you need to change the definition of the Media Browser in the "\App_Config\Include\Sitecore.Speak.config" file like this:

Default config:

Tree view config:

The result will look like this: