Software update stuck on 'preparing updates'

We can't see your machine or device, much less read your mind. We rely on you to give us enough information so that we can understand your issue if we are to help. We need a full description of the issue, information on what devices or machines you're referring to, the operating system (and version of it) currently on the machine. What you expect to happen, and where it fails. Err on giving too much information rather than too little.