Hey Scott,
Thanks for your input!

I didn't realize that the Spindle Control was a separate exe file. I ran it on our 2nd machine and it adjusted the speed perfectly.

Later, when we have a bit of down time I'll try moving it to the virtual tools folder on the Primary computer.

What do you think about drivers? Will my Primary computer (with the old software) know what to do when I plug the VFD's USB into it?