Hi John, I have seen this message when installing / upgrading EPDM. In my experience, I use the second option (Do not close applications) and have never had any issues with this.
My bigger concern would be that you are installing EPDM 2013 on Windows 10, which is not a supported environment. See this link for details:
That's not to say it won't install and work (clearly you are installing it), but just be aware that if issues do arise, your VAR and SolidWorks will most likely point to that first.
Or just simply point out that EPDM 2013 is not going to receive any updates/supported at all!
Only three active versions correct- 2014, 2015, 2016.