Installing Visual Studio Versions Side-by-Side
You can install this version of Visual Studio on a computer that already has an earlier version installed. If you encounter an installation failure, you can use the log collection tool to collect information about the failures so you can debug the issues yourself.
We recommend that you install Visual Studio versions in the order in which they were released. For example, install Visual Studio 2013 before you install Visual Studio 2015.
Before you install versions side by side, review the following conditions:
If you use Visual Studio 2015 to open a solution that was created in Visual Studio 2013, you can later open and modify the solution again in the older version as long as you haven't implemented any features that are specific to Visual Studio 2015.
If you try to use Visual Studio 2015 to open a solution that was created in Visual Studio 2013 or an earlier version, you might need to modify your projects and files to be compatible with Visual Studio 2015. For more information, see Porting, Migrating, and Upgrading Visual Studio Projects.
If you uninstall a version of Visual Studio on a computer that has more than one version installed, the file associations for Visual Studio are removed for all versions. You can remap these file associations by using the Restore File Associations button on the Environment, General page of the Options dialog box.
Visual Studio doesn't automatically upgrade extensions because not all extensions are compatible. You must reinstall the extensions from the Visual Studio Gallery or the software publisher.
Visual Basic, Visual C#, and Visual F# projects use the Target Framework option in the Project Designer to specify which version of the .NET Framework a project uses. For a C++ project, you can manually change the target framework by modifying the .vcxproj file. For more information, see Version Compatibility in the .NET Framework.
When you create a project, you can specify which version of the .NET Framework the project targets in the .NET Framework list in the New Project dialog box.
For language-specific information, see the appropriate topic in the following table.