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Registers project or item templates that are located in <Visual Studio installation path>\Common7\IDE\ProjectTemplates\ or <Visual Studio installation path>\Common7\IDE\ItemTemplates\ so that they can be accessed through the New Project and Add New Item dialog boxes.
This switch is supported only for Visual Studio partner development, and is not available in Express editions. You must run devenv as an administrator in order to use the /Setup (devenv.exe) and /InstallVSTemplates (devenv.exe) switches. For more information, see User Permissions.