How to: Upgrade Office Solutions
If you have a Microsoft Office project that was created in an earlier version of Visual Studio, the project will upgrade automatically when you open it in Visual Studio 2013. After you upgrade the project, it will work just as it did in earlier versions of Visual Studio.
For more information about the Microsoft Office projects you can upgrade and the specific changes that Visual Studio makes to upgraded projects, see Upgrading and Migrating Office Solutions.
To upgrade a Microsoft Office project
Open a solution that contains an existing project in a version of Visual Studio 2013 that includes the Microsoft Office developer tools.
For more information, see Configuring a Computer to Develop Office Solutions. Visual Studio creates a backup of your solution and adds the backup files to your solution directory. The solution opens with the new project system visible in Solution Explorer.