To support 32- and 64-bit targets in a single .vcproj file, you simply add the 64-bit platform. The following procedure shows how to do this through the Visual Studio IDE.
To add the x64 target platform to a 32-bit project
- In the Build menu, select Configuration Manager.
- Select New Configuration from the Active Solution Platform drop-down menu.
- Select the x64 option from the Type or Select the New Platform drop-down list. If you do not see the x64 option, you have not installed the proper 64-bit compiler.