On many corporate networks every single piece of software and version must be pre-approved before use.  Automatically updating software without the consent of the user is unacceptable. Despite having unchecked the "automatically notify me of available updates", SourceTree will still update itself without the user's permission. There must be a way to disable this via the user interface.  Alternatively, the default behavior should be only to notify the user of updates but require the user to initiate the upgrade.