Setting the Active Build Configuration
There are three ways to set active build configuration for your solution. You can change it from the Build menu and Solution Properties Grid.
To change the settings for a particular configuration and project
In the Project Explorer, select a project.
On the Project menu, click Properties.
From the Configuration drop-down control, choose Debug, Release, or All Configurations.
To change the build configuration on the menu
On the Build menu, click Build Configuration.
From the drop-down list, choose Debug or Release.
To set the active build configuration on the Solution Properties Grid
Select the solution.
On the Solution Properties Grid, the configuration entry appears, named ActiveCfg, with Debug or Release as a value.
Click the drop-down list arrow to the right of the value to change it.