Software installation, configuration and updates can sometimes be a bit of a gamble. Will the software come with easily understandable instructions? Will you need to uninstall the old software first? Most software, being Windows, Microsoft Office or Sage, for example, do come with an installer, which simplifies the process dramatically.
For example you may be an accountancy firm who use software to hold Tax records and Client details in a database. A new version of your software becomes available. It is wise to have software installed and updated professionally to ensure peace of mind.