/Setup (devenv.exe)
Visual Studio 2012
Forces Visual Studio to merge the resource metadata that describes menus, toolbars, and command groups, from all available VSPackages.
devenv /setup
This switch takes no arguments. The devenv /setup command is typically given as the last step of the installation process. Use of the /setup switch does not start Visual Studio.
You must run devenv as an administrator in order to use the /Setup (devenv.exe) and /InstallVSTemplates (devenv.exe) switches.