I've created a small XLL add-in using Visual C++ 2008, and when I use
it on the development machine, it works perfectly fine. When I
distribute it to the user who asked me to develop it, he can't get it
to load on his machine. Based on my testing, it fails to load
properly on any machine that does not have Visual Studio installed,
but works perfectly fine on any machine that does have Visual Studio
installed (even if it wasn't compiled on that machine).

I suspect that it's a compiler switch that's set wrong or that the XLL
is somehow dependent on a VS2008 file, but I have no idea what to look
for (I'm not a professional programmer; I'm an engineer that's
particularly proficient at programming, so there are significant gaps
in my expertise).

If anyone has any suggestions, I'd love to hear them.

Thanks,

Greg