Had a powerPivot application running perfectly with Windows 10 and EXCEL 365, but user has Office 10, so the 365 app would not run on that machine. I uninstalled Office 365 and installed Office 10 on my machine, and down loaded and installed PowerPivot. But when I try to enable PowerPivot in EXCEL 2010 by going to File->Options-> Add-Ins and in the Manage: box, select COMM Add-Ins and click Go... Then put a check mark in the PowerPivot for Excel box, it does not load. I click OK, PowerPivot does not appear in the ribbon, and the check mark is gone from the PowerPivot in Add-Ins available window. I close Options and reopen and there is a message after "Load Behavior" that says "Not Loaded. A runtime error occurred during the loading of the COMM add-in." I've searched the web and can find no workable solution.
Office 2010, 32 bit, Windows 10