To get Analytic Solver to work in Excel, you need to register the plugin before launching Excel.
First, open Excel, open a blank worksheet, then close Excel (if you've never used Excel on this specific computer before).
Then, once Excel is closed, click on
Start --> Frontline Systems --> Analytic Solver Platform --> ASP Application Manager
This will produce a box that will allow you to register or unregister the Analytic Solver plugin. Once you have registered the plugin, open Excel and you will see the Analytic Solver ribbons across the top.