.NET Framework Launch Condition
The .NET Framework launch condition is used to check for the common language runtime on a target computer during installation. This launch condition is automatically added to a deployment project when a dependency on the .NET Framework is detected; it cannot be removed.
If a version of the runtime specified in the SupportedRuntimes property is not found, the installation is halted. The user is presented with a Yes / No dialog box containing the text specified in the Message property. If the user chooses Yes, he is redirected to the location specified in the InstallUrl property (the default is a Microsoft Support Web site that contains a downloadable copy of the .NET Framework redistributable file).
In many cases, you will want to modify the InstallUrl property to point to your own location for the redistributable file. For example, if you are distributing your application on CD-ROM, you should include the redistributable file on the CD and change the InstallUrl property to a relative file path. If you change the InstallUrl property, you should also change the Message property to explain what is being installed and from where.
In addition, any Visual Studio .NET application or component that includes data access has a dependency on Microsoft Data Access Components (MDAC) version 2.7 or later. You will also need to add a launch condition to check for MDAC if your application includes data access. For more information, see Adding a Launch Condition for Microsoft Data Access Components.
Launch Condition Management in Deployment | SupportedRuntimes Property | Message Property | InstallUrl Property | Working With Multiple Versions of the .NET Framework | Side-by-Side Execution | Properties for the Launch Conditions Editor