Use of Visual C/C++ 6.0 is not supported on Windows 10 (unless you can follow off-site policy installation procedures). So, on new PC, USB8451 is only usable with Labview.
In other words, with more than 400$ you'll buy a device that, without buying Labview, could be only used as a paperweight.
I believe that in order to have sense, USB8451 device need a .net solution (easily developed starting from existing VC6 .dll) to be used also by vb/vba/etc.
Really disappointed.