I have .NET 2.0 runtime installed, then I installed the .NET 4.0 runtime, so I have both. When I run a .NET app, is there a way to force which runtime will be used?
Take a look: Configuring Assembly Binding Redirection
By default, applications use the set of .NET Framework assemblies that shipped with the runtime version used to compile the application. You can use the appliesTo attribute on the
<assemblyBinding>
element in an application configuration file to redirect assembly binding references to a specific version of the .NET Framework assemblies. This optional attribute uses a .NET Framework version number to indicate which version it applies to. If no appliesTo attribute is specified, the<assemblyBinding>
element applies to all versions of the .NET Framework.
Yes, use the <supportedRuntime> element in the .exe.config file. For example:
<configuration>
<startup>
<supportedRuntime version="v2.0.50727"/>
</startup>
</configuration>
Here's a list of MSDN reference to target specific .NET Framework version for VS.NET projects:
How to: Target a Specific .NET Framework
Visual Studio 2010
How to: Target a Specific .NET Framework Version or Profile