Legacy apps
If you are deciding whether or not to upgrade to Windows 8.1 from Windows 7, you need to consider various things. The first point to bear in mind pertains to you if you're running a business and are installing Windows 8.1 onto multiple computers, all of which will need legacy apps and services.
If this is the case, Windows 8.1 may not be an advisable choice unless absolutely necessary. While Microsoft has implemented some more mouse-friendly features, the operating system remains predominately designed for a tablet with an awkward transition to the Desktop mode when legacy apps are called upon.