Pre-launch is a feature of XenApp/XenDesktop that allows application and desktop sessions to start faster. This is done by pre-launching the resource upon first access and thus making it more responsive on subsequent access.
Note: PreLaunch is implicitly enabled if Receiver is configured for domain pass through (SSON) authentication.
If you enable this policy setting, the Session/Application Pre-launch functionality is enabled.
If you disable this policy setting, also disables the Session/Application Pre-launch functionality.