Need Help Opening Opponent K'43 file

[HirooOnoda]

I uploaded a shot of my opponent's saved game file.
I'm playing K'43 on the same machine I have always played it on, but I suspect that since machine upgraded to Windows 10 the security procedures have changed. 

When I unzip his file All that shows up is a great, big "E" (as in window's explorer). It says it saved the file as a .bte in the saved game folder, but when I open K'43 to load my opponent's turn it isn't there.  

Ideas?