VSConstants::UICONTEXT::FirstLaunchSetup_string Field

Specifies a context in which the first launch after setup is in progress. Packages may use ProvideAutoLoad with this UI context to perform expensive one-time per-user initialization. Note that during the first launch after setup, many services are unavailable and a package may not display any UI. The first launch after setup is not guaranteed to be called; it is just an opportunity for packages to build caches.