If you have this issue, then the easiest solution is to use the specially modified versions of the MS-Office Add-Ins in this article that have the pre-requisite checking disabled.

This does mean that you will need to manually make sure that you do have VSTO 10.0 (or later) already installed. If you don't then you won't see the Excel, Word or MS-Project ribbon entry appear as expected.

We therefore recommend you always try the standard version from our website first, before using these modified versions.